U.S. patent application number 17/500082 was filed with the patent office on 2022-04-14 for method of using metal organic framework.
This patent application is currently assigned to PHILLIPS 66 COMPANY. The applicant listed for this patent is PHILLIPS 66 COMPANY. Invention is credited to Camille Malonzo May, Jose Edgar Mendez-Arroyo, Jianhua Yao.
Application Number | 20220111370 17/500082 |
Document ID | / |
Family ID | 1000005956083 |
Filed Date | 2022-04-14 |
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United States Patent
Application |
20220111370 |
Kind Code |
A1 |
May; Camille Malonzo ; et
al. |
April 14, 2022 |
METHOD OF USING METAL ORGANIC FRAMEWORK
Abstract
A process comprising a heterogeneous reaction between a solid
metal organic framework supported catalyst and a hydrocarbon feed
to form a modified hydrocarbon stream. The modified hydrocarbon
stream comprises essentially of C6+ hydrocarbons.
Inventors: |
May; Camille Malonzo;
(Collinsville, TX) ; Mendez-Arroyo; Jose Edgar;
(Bartlesville, OK) ; Yao; Jianhua; (Bartlesville,
OK) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
PHILLIPS 66 COMPANY |
HOUSTON |
TX |
US |
|
|
Assignee: |
PHILLIPS 66 COMPANY
HOUSTON
TX
|
Family ID: |
1000005956083 |
Appl. No.: |
17/500082 |
Filed: |
October 13, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
63091060 |
Oct 13, 2020 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B01J 2531/62 20130101;
B01J 2531/48 20130101; B01J 2231/20 20130101; B01J 31/1691
20130101; C07C 2531/06 20130101; C07C 2/58 20130101; B01J 2231/44
20130101; B01J 2531/49 20130101 |
International
Class: |
B01J 31/16 20060101
B01J031/16; C07C 2/58 20060101 C07C002/58 |
Claims
1) A process comprising: a heterogenous reaction between a solid
metal organic framework supported catalyst and a hydrocarbon feed
to form a modified hydrocarbon stream; wherein the modified
hydrocarbon stream comprises essentially of C6+ hydrocarbons.
2) The process of claim 1, wherein the catalyst is selected from
the group consisting of: oxyanion-modified metal oxide,
heteropolyacids, sulfonic acids, ionic liquids, and combinations
thereof.
3) The process of claim 1, wherein the heterogenous reaction is an
alkylation reaction.
4) The process of claim 1, wherein the heterogenous reaction is an
oligomerization reaction.
5) The process of claim 1, wherein the hydrocarbon feed is selected
from the group consisting of a gaseous hydrocarbon feed, a liquid
hydrocarbon feed, or a supercritical hydrocarbon feed.
6) The process of claim 1, wherein the process is able to achieve a
conversion to C6+ hydrocarbons greater than 30%.
7) The process of claim 1, wherein the process is able to achieve a
selectivity of C6+ hydrocarbons greater than 30%.
8) The process of claim 1, wherein the hydrocarbon feed comprises
essentially of C2 to C5 hydrocarbons.
9) A process comprising: a heterogeneous reaction between a solid
metal organic framework supported catalyst; and a liquid
hydrocarbon feed, consisting essentially of C2 to C5 hydrocarbons,
to form a modified hydrocarbon stream, wherein the modified
hydrocarbon stream comprises essentially of C6+ hydrocarbons.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a non-provisional application which
claims the benefit of and priority to U.S. Provisional Application
Ser. No. 63/091,060 filed Oct. 13, 2020, entitled "Methods of
Selection, Forming, and Using Metal Organic Frameworks," which is
hereby incorporated by reference in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] None.
FIELD OF THE INVENTION
[0003] Method of using metal organic framework
BACKGROUND OF THE INVENTION
[0004] Acid catalysts are critical for industrial hydrocarbon
transformations. Reactions such as cracking, alkylation,
isomerization, oligomerization and hydration/dehydration, which are
important steps in the production of chemicals and fuels, are acid
catalyzed. The acid strength requirement for the catalysts differ
for these processes.
[0005] Solid acids are deemed easier to handle and more
environmentally benign than liquid acids. Some important families
of solid acid catalysts include zeolites, oxides, clays, and
polymer resins. These catalyst families are under continuous
development to achieve new reactivities and improve catalytic
performance.
[0006] Metal-organic frameworks (MOFs) are emerging as a promising
class of heterogeneous catalysts due to their unique physical and
chemical properties including high surface area, adjustable pore
structure, tunable element composition, and the potential for
surface modification. MOFs are porous, crystalline materials made
of alternating organic (linkers) and inorganic building units
(nodes). Importantly, their well-defined molecular structure and
chemical environment enable the catalytic conversion of complex
feedstocks into products with high selectivity and high conversion.
The interest in MOFs in the field of catalysis has been attributed
to the ability of these materials to bridge the gap between
homogenous and heterogenous catalysis. This is due to the ability
of MOFs to recreate chemically precise catalytic active sites such
as those found in homogenous catalysis in a heterogenous support.
In recent years, acidic MOFs have attracted significant research
interest because of their potential application in a large class of
acid-catalyzed reactions, including isomerization, cyclization,
biomass transformation, benzylation, and aromatic alkylation.
[0007] An important refinery process that requires high acid
strength catalysts is olefin-paraffin alkylation. The alkylation
process produces high-octane gasoline blend called alkylate by
reacting light olefins (C.sub.2-C.sub.4) with isoparaffins
(C.sub.4-C.sub.5). Most commonly, isobutane is reacted with olefins
(butenes) derived from refinery fluid catalytic cracking units to
produce a product that consists of C.sub.6-C.sub.9 branched
paraffins. Out of all the desired products, trimethylpentanes
(TMPs) are typically the primary component. TMPs have research
octane numbers (RONs) of 100-109.6. Other lower-octane reaction
products such as dimethylhexanes (DMHs) and dimethylpentanes are
also present.
[0008] For alkylation, the current catalyst systems used in
refineries are liquid hydrofluoric acid (HF) and sulfuric acid
(H.sub.2SO.sub.4). These strong acids are required to promote the
hydride transfer reaction between an isoparaffin and hydrocarbon
carbocation. Alternative alkylation catalysts are of interest
because of risks associated with traditional HF- and
H.sub.2SO.sub.4-based alkylation. Catalysts such as zeolites, ionic
liquids (ILs), heteropolyacids (HPAs), acidic resins, and sulfated
transition metal oxides (TMOs) have been shown to catalyze
alkylation, but technical challenges--including low activity and
rapid deactivation--exist.
[0009] Similarly, to alkylation, oligomerization is a hydrocarbon
upgrading process that is an attractive, low-cost means to lower
the vapor pressure of light naphtha streams that may be orphaned by
future regulatory standards. This process can take olefins in the
gas phase (C.sub.2-C.sub.4) and convert them to heavier liquid
hydrocarbons suitable to a large array of applications such as:
naphtha (C.sub.6-C.sub.9), diesel (C.sub.9-C.sub.12), jet fuel
(C.sub.12-C.sub.16) and specialty chemicals. In order to undergo
oligomerization, a source of acidity is also required much like in
alkylation chemistry. This is due because both reactions sharing a
common intermediate which is a carbocation formed when an olefin is
protonated and stabilized in the surface of the catalyst. In
oligomerization, there is no requirement for hydride transfer in
the reaction mechanism allowing the process to occur with lower
acidity requirements as compared to alkylation. Nevertheless, an
important correlation exists wherein the smaller the olefin, the
higher the acidity required to oligomerize the feed. Thus, high
acidity materials have a larger operating window since they can
utilize a wider range of feeds.
[0010] Materials for oligomerization can be found in the literature
and often overlap with materials used for alkylation due to the
shared chemical intermediates between both processes. These
materials include: Aluminosilicates, zeolites, ionic liquids (ILs),
heteropolyacids (HPAs), acidic resins, and sulfated transition
metal oxides (TMOs). Despite the broad range of materials, a
diverse set of challenges exist. In many cases fast deactivation is
observed due to formation of large oligomers that block the
channels of materials and high conversion often is accompanied by
poor selectivity to the desired products.
BRIEF SUMMARY OF THE DISCLOSURE
[0011] A process comprising a heterogeneous reaction between a
solid metal organic framework supported catalyst and a hydrocarbon
feed to form a modified hydrocarbon stream. The modified
hydrocarbon stream comprises essentially of C6+ hydrocarbons.
[0012] A process comprising a heterogeneous reaction between a
solid metal organic framework supported catalyst and a liquid
hydrocarbon feed to form a modified hydrocarbon stream. The
modified hydrocarbon stream comprises essentially of C6+
hydrocarbons.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] A more complete understanding of the present invention and
benefits thereof may be acquired by referring to the follow
description taken in conjunction with the accompanying drawings in
which:
[0014] FIG. 1 depicts linkers currently used to build MOFs.
[0015] FIG. 2 depicts results from analysis of MOFs.
[0016] FIG. 3 depicts results from analysis of MOFs.
[0017] FIG. 4 depicts results from analysis of MOFs.
[0018] FIG. 5a depicts conversion v. catalyst age alkylation
results.
[0019] FIG. 5b depicts selectivity v. conversion results.
[0020] FIG. 6a depicts conversion v. catalyst age alkylation
results.
[0021] FIG. 6b depicts selectivity v. conversion results.
[0022] FIG. 7a depicts conversion v. catalyst age alkylation
results.
[0023] FIG. 7b depicts selectivity v. conversion results.
[0024] FIG. 8a depicts supercritical alkylation results.
[0025] FIG. 8b depicts supercritical alkylation results.
[0026] FIG. 9 depicts activation results.
[0027] FIG. 10 depicts selectivity results.
[0028] FIG. 11 depicts a reaction scheme.
[0029] FIG. 12 depicts example MOF building units.
[0030] FIG. 13 depicts example MOF ligands.
[0031] FIG. 14 depicts non-limiting representative sultones.
[0032] FIG. 15 depicts alkylation results.
[0033] FIG. 16 depicts alkylation results.
[0034] FIG. 17 depicts alkylation results.
[0035] FIG. 18 depicts supercritical alkylation results.
[0036] FIG. 19 depicts the alkylation results.
[0037] FIG. 20 depicts the alkylation results.
[0038] FIG. 21 depicts the alkylation results.
[0039] FIG. 22 depicts the oligomerization results.
[0040] FIG. 23 depicts the product selection results.
[0041] FIG. 24 depicts the conversion results.
[0042] FIG. 25 depicts long term stability results.
[0043] FIG. 26 depicts a non-limiting embodiment of the
process.
[0044] FIG. 27 depicts oligomerization results.
DETAILED DESCRIPTION
[0045] Turning now to the detailed description of the preferred
arrangement or arrangements of the present invention, it should be
understood that the inventive features and concepts may be
manifested in other arrangements and that the scope of the
invention is not limited to the embodiments described or
illustrated. The scope of the invention is intended only to be
limited by the scope of the claims that follow.
[0046] A process comprising a heterogeneous reaction between a
hydrocarbon feed on a solid metal-organic framework--supported or
based catalyst to form a modified hydrocarbon stream comprising
essentially of C.sub.6+ hydrocarbons. Non-limiting examples of
MOFs-supported catalytically active components that can be used
include heteropolyacids, sulfonic acids, oxyanions such as
oxyanions-modified metal oxides, and ionic-type
functionalities.
[0047] This arrangement details the preparation of different types
of acidic MOF-based catalysts and their applications. The MOF-based
catalysts can consist of two components: the MOF support and the
acid sites that are bound to the MOF support. The acid sites can
dictate the acid strength and therefore the type of reaction that
can be catalyzed by the MOF based catalysts. Different acid sites
require different binding motifs on the MOF support. The acid site
can be encapsulated in the pore space of the MOF, or it could be
bound to the MOF by attachment to the MOF node, linker or any
non-linker ligand present in the MOF structure. The acid sites can
be incorporated in the MOF support during the synthesis of the MOF,
or they can be introduced to the MOF post-synthesis. The MOF
support can influence mass diffusion, acid site dispersion and
environment related to catalytic activity.
[0048] In a non-limiting example, the MOF support features a
suitable pore and aperture size to encapsulate the acid
species.
[0049] In a non-limiting example, the MOF support features
nucleophilic groups such as hydroxyl, amino, thiol, and phosphine,
among others. These groups can serve as attachment points for the
acid species.
[0050] In a non-limiting example, the MOF support features a
suitable metal oxide-based node that interacts with an anionic
species to form an acid site.
[0051] In other non-limiting examples, the catalytically active
components can be added to the solid metal organic frameworks via
solution impregnation, one-pot synthesis, encapsulation,
adsorption, deposition, grafting and/or covalent attachment
reactions.
[0052] In one embodiment the loading of the catalytic active
components on the solid metal organic framework can be greater than
5% by weight, or in other embodiments even 10%, 15%, 20%, 25%, 30%,
35%, 40%, 45%, 50%, 55%, 60%, 65%, even 70% or more by weight.
[0053] In addition, this arrangement describes the composition of a
new family of acidic MOFs bearing halogenated and/or
non-halogenated sulfonic acid functionalities as acid sites for use
as alternative solid acid catalysts for different organic
transformations. The reactivity of this family of MOFs can be tuned
by changing the type of MOF and sulfonic acid functionality to meet
catalytic application demands. In one example, the sulfonic acid
functionalized MOF has enough strength to catalyze the
olefin-paraffin alkylation reaction.
[0054] The heterogeneous reaction can be either an olefin-paraffin
alkylation reaction or an olefin oligomerization reaction. As an
example, for some alkylation reactions, the hydrocarbon component
produced is a C.sub.6+ paraffinic hydrocarbon. As another example,
for some oligomerization reactions, the hydrocarbon component
produced is a C.sub.6+ olefinic hydrocarbon or even an C.sub.8+
olefinic hydrocarbon.
[0055] In one embodiment, the hydrocarbon feed comprises and/or
comprises essentially of C.sub.2 to C.sub.5 hydrocarbons such as
light hydrocarbons. These light hydrocarbons feed can be olefins
such as propylene, butylene and/or isoparaffins such as isobutane.
In another embodiment, the heterogenous reaction between a solid
metal organic framework and a hydrocarbon feed which can be a
gaseous hydrocarbon feed, a liquid hydrocarbon feed, or a
supercritical hydrocarbon feed.
[0056] In this arrangement, we describe a process that uses an
acidic MOF that can convert a hydrocarbon feed of light olefins
(C.sub.3-C.sub.6) and isoparaffins (C.sub.4-C.sub.5) to heavier,
more valuable products, such as alkylate which is a blend stock for
high octane gasoline. This product effluent is forecasted to have
great growth potential despite the forecasted changes in gasoline
demand. In the refining process many of these hydrocarbon feeds or
light olefins (especially C4s) end up as feedstock for processes
such as alkylation which can produce valuable alkylate, such as
high octane gasoline components.
[0057] In this arrangement we describe a new process that uses an
acidic MOF that can selectively oligomerize a hydrocarbon feed of
light olefins (C.sub.3-C.sub.6) to heavier more valuable products
such as the modified hydrocarbon stream which can be high octane
gasoline, low sulfur diesel, jet fuel, specialty solvents or
synthetic lube oils, which have been forecast to have great growth
potential despite the forecasted changes in gasoline demand.
[0058] In another embodiment, the proposed arrangement utilizes the
high selectivity of the MOF material and engineered conditions to
integrate oligomerization and alkylation to maximize the value of
the product stream. In this integrated process, the low value
olefins are selectively oligomerized while the high value olefins
are alkylated to form high octane gasoline components.
[0059] In a non-limiting embodiment, the process is able to achieve
a modified hydrocarbon stream with a conversion rate of C.sub.6+
hydrocarbons at a rate greater than 20%, 25%, 30%, 35%, 40%, 45%,
50%, 55%, even greater than 60%.
[0060] In a non-limiting embodiment, the process is able to achieve
a modified hydrocarbon stream with a selectivity rate of C.sub.6+
hydrocarbons at a rate greater than 20%, 25%, 30%, 35%, 40%, 45%,
50%, 55%, even greater than 60%.
[0061] Other potential applications for acid MOFs include olefin
oligomerization, C.sub.2-C.sub.4 olefins/i-C.sub.4 and iC.sub.5
isoparaffin alkylation, olefin isomerization, and olefin/aromatic
alkylation.
[0062] MOF Supports
[0063] MOB are built up of metal cation containing nodes bridged by
organic linkers. Non-limiting examples of linkers and nodes that
can be used are generally described below.
[0064] MOF Linkers and Non-Linker ligands
[0065] The organic linkers of the MOFs of the arrangement may be
any linker molecule or molecule combination capable of binding to
at least two inorganic nodes and comprising an organic moiety.
Thus, the linker may be any of the linkers conventionally used in
MOF production. These are generally compounds with at least two
node-binding groups, e.g. carboxylates, optionally with extra
functional groups which do not bind the nodes but may bind metal
ions on other materials it is desired to load into the MOF. The
linkers moreover typically have rigidifying groups between the
node-binding groups to facilitate 3D MOF formation. Examples of
suitable organic linker compounds include oxalic acid, ethyloxalic
acid, fumaric acid, 1,3,5-benzene tricarboxylic acid (BTC),
1,3,6,8-tetrakis(p-benzoic acid)pyrene (TBAPy), 1,3,5-benzene
tribenzoic acid (BTB), DCPB, benzene tribiphenylcarboxylic acid
(BBC), 5,15-bis(4-carboxyphenyl) zinc (II) porphyrin (BCPP),
1,4-benzene dicarboxylic acid (BDC), 2-amino-1,4-benzene
dicarboxylic acid (R3-BDC or H2N BDC), 1,1'-azo-diphenyl
4,4'-dicarboxylic acid, cyclobutyl-1,4-benzene dicarboxylic acid
(R6-BDC), benzene tricarboxylic acid, 2,6-naphthalene dicarboxylic
acid (NDC), 1,1'-biphenyl 4,4'-dicarboxylic acid (BPDC),
2,2'-bipyridyl-5,5'-dicarboxylic acid, adamantane tetracarboxylic
acid (ATC), adamantane dibenzoic acid (ADB), adamantane
teracarboxylic acid (ATC), dihydroxyterephthalic acid (DHBDC),
biphenyltetracarboxylic acid (BPTC), tetrahydropyrene
2,7-dicarboxylic acid (HPDC), dihydroxyterephthalic acid (DHBC),
pyrene 2,7-dicarboxylic acid (PDC), pyrazine dicarboxylic acid,
acetylene dicarboxylic acid (ADC), camphor dicarboxylic acid,
fumaric acid, benzene tetracarboxylic acid,
1,4-bis(4-carboxyphenyl)butadiyne, nicotinic acid, and terphenyl
dicarboxylic acid (TPDC). Other acids besides carboxylic acids,
e.g. boronic acids may also be used. A mixture of linkers may be
used to introduce functional groups within the pore space, e.g. by
using aminobenzoic acid to provide free amine groups or by using a
shorter linker such as oxalic acid.
[0066] In one embodiment, the linker comprises an organic-based
parent chain comprising alkyl, hetero-alkyl, alkenyl,
hetero-alkenyl, alkynyl, hetero-alkynyl, one or more cycloalkyl
rings, one or more cycloalkenyl rings, one or more cycloalkynyl
rings, one of more aryl rings, one or more heterocycle rings, or
any combination of the preceding groups, including larger ring
structures composed of linked and/or fused ring systems of
different types of rings; wherein this organic-based parent chain
may be further substituted with one or more functional groups,
including additional substituted or unsubstituted hydrocarbons and
heterocycle groups, or a combination thereof; and wherein the
linker contains at least one (e.g. 1, 2, 3, 4, 5, 6, . . . )
linking cluster.
[0067] In a yet further embodiment, the linker of the metal organic
framework has an organic-based parent chain that is comprised of
one or more substituted or unsubstituted rings; wherein one or more
of these rings are further substituted with one or more functional
groups, including additional substituted or unsubstituted
hydrocarbons and heterocycle groups, or a combination thereof; and
wherein the linker contains at least one (e.g., 1, 2, 3, 4, 5, 6,
or more) linking cluster that is either a carboxylic acid, amine,
thiol, cyano, nitro, hydroxyl, or heterocycle ring heteroatom, such
as the N in pyridine.
[0068] In another embodiment, the linker of the metal organic
framework has an organic-based parent chain that is comprised of
one or more substituted or unsubstituted rings; wherein one or more
of these rings are further substituted with one or more functional
groups, including additional substituted or unsubstituted
hydrocarbons and heterocycle groups, or a combination thereof; and
wherein the linker contains at least one (e.g., 1, 2, 3, 4, 5, 6,
or more) carboxylic acid linking cluster.
[0069] The non-linker ligands of the MOFs of the arrangement may be
any ligand molecule or molecule combination capable of binding to
one inorganic node and comprising an organic moiety. These are
generally compounds with one node-binding group, e.g. carboxylates,
with or without extra functional groups that do not bind the nodes
but may react with and/or bind other species such as electrophiles
and acid site precursors that are desired to be used to
functionalize the MOF.
[0070] In a certain embodiment the pore aperture of the MOF support
is controlled by the length of the linker.
[0071] MOF Nodes
[0072] The inorganic nodes of MOFs can be synthesized using metal
ions having distinctly different coordination geometries, in
combination with a ligand possessing multidentate functional
groups, and a suitable templating agent. In general, the inorganic
nodes could be one or more metal-based nodes from Group 1 through
16 metals of the IUPAC Periodic Table of the Elements including
actinides, and lanthanides, and combinations thereof. Examples of
metal ions in the node can include: Mg.sup.2+, Ca.sup.2+,
Sr.sup.2+, Ba.sup.2+, Sc.sup.3+, Y.sup.3+, Ti.sup.4+, Zr.sup.4+,
Ce.sup.4+, Hf.sup.4+, V.sup.4+, V.sup.3+, V.sup.2+, Nb.sup.3+,
Ta.sup.3+, Cr.sup.3+, Mo.sup.3+, W.sup.3+, Mn.sup.3+, Mn.sup.2+,
Re.sup.3+, Re.sup.2+, Fe.sup.3+, Fe.sup.3+, Ru.sup.3+, Ru.sup.2+,
Os.sup.3+, Os.sup.2+, Co.sup.3+, Co.sup.2+, Rh.sup.2+, Rh.sup.+,
Ir.sup.2+, Ir.sup.+, Ni.sup.2+, Ni+, Pd.sup.2+, Pd.sup.+,
Pt.sup.2+, Cu.sup.2+, Cu.sup.+, Ag.sup.+, Au.sup.+, Zn.sup.2+,
Cd.sup.2+, Hg.sup.2+, Al.sup.3+, Ga.sup.3+, In.sup.3+, Tl.sup.3+,
Si.sup.4+, Si.sup.2+, Ge.sup.4+, Ge.sup.2+, Sn.sup.4+, Sn.sup.2+,
Pb.sup.4+, Pb.sup.2+, As.sup.5+, As.sup.3+, As.sup.+, Sb.sup.5+,
Sb.sup.3+, Sb.sup.+, and Bi.sup.5+, Bi.sup.3+, Bi.sup.+; along with
the corresponding metal salt counteranion. As used herein, the
nodes refer to both metal and metalloid ions. Generally, the nodes
that can be useful include: Sc.sup.3+, Zr.sup.4+,
Ce.sup.4+Hf.sup.4+, Ti.sup.4+, V.sup.4+, V.sup.3+, V.sup.2+,
Cr.sup.3+, Mo.sup.3+, Mn.sup.3+, Mn.sup.2+, Fe.sup.3+, Fe.sup.2+,
Ru.sup.3+, Ru.sup.2+, Os.sup.3+, Os.sup.2+, Co.sup.3+, Co.sup.2+,
Rh.sup.2+, Rh.sup.+, Ir.sup.2+, Ir.sup.+, Ni.sup.+, Pd.sup.2+,
Pd.sup.+, Pt.sup.2+, Pt.sup.+, Cu.sup.2+, Cu.sup.+, Ag.sup.+,
Au.sup.+, Zn.sup.2+, Cd.sup.2+, Al.sup.3+. Al.sup.3+, Ga.sup.3+,
In.sup.3+, Ge.sup.4+, Ge.sup.2+, Sn.sup.4+, Sn.sup.2+, Pb.sup.4+,
Pb.sup.2+, Sb.sup.5+, Sb.sup.3+, Sb.sup.+, and Bi.sup.5+,
Bi.sup.3+, Bi.sup.+; along with the corresponding metal salt
counteranion. A preferred group of nodes includes: Sc.sup.3+,
Zr.sup.4+, Ce.sup.4+, Hf.sup.4+, Ti.sup.4+, V.sup.4+, V.sup.3+,
Cr.sup.3+, Mo.sup.3+, Mn.sup.3+, Mn.sup.2+, Fe.sup.3+, Fe.sup.2+,
Co.sup.3+, Co.sup.2+, Ni.sup.2+, Ni.sup.+, Cu.sup.2+, Cu.sup.+,
Ag.sup.+, Zn.sup.2+, Cd.sup.2+, Al.sup.3+, Sn.sup.4+, Sn.sup.2+,
and Bi.sup.5+, Bi.sup.3+, Bi.sup.+; along with the corresponding
metal salt counteranion. More preferably the nodes used are
selected from the group consisting of: Zr.sup.4+, Ce.sup.4+,
Hf.sup.4+, Cr.sup.3+, Mn.sup.3+, Mn.sup.2+, Fe.sup.3+, Fe.sup.2+,
Co.sup.3+, Co.sup.2+, Ni.sup.2+, Ni.sup.+, Cu.sup.2+, Cu.sup.+,
Ag.sup.+, Zn.sup.2+, Cd.sup.2+, Al.sup.3+ along with the
corresponding metal salt counteranion. Most preferably the nodes
useful in this arrangement are selected from the group consisting
of: Zr.sup.4+, Hf.sup.4+, Cr.sup.3+, Fe.sup.3+, Fe.sup.2+,
Co.sup.3+, Co.sup.2+, Ni.sup.2+, Ni.sup.+, Cu.sup.2+, Cu.sup.+,
Zn.sup.2+, Al.sup.3+ along with the corresponding metal salt
counteranion. An especially preferred group of nodes that can be
used include: Zr.sup.4+, Ce.sup.4+, Hf.sup.4+, Cr.sup.3+,
Fe.sup.3+, Co.sup.3+, Co.sup.2+, Ni.sup.2+, Ni.sup.+, Zn.sup.2+,
Al.sup.3+ along with the corresponding metal salt counteranion.
[0073] In yet another embodiment, one or more metals that can be
used in the (1) synthesis of frameworks, (2) exchanged post
synthesis of the frameworks, and/or (3) added to a framework by
forming coordination complexes with post framework reactant
functional group(s) include, but are not limited to, Li.sup.+,
Na.sup.+, K.sup.+, Rb.sup.+, Cs.sup.+, Be.sup.2+, Mg.sup.2+,
Ca.sup.2+, Sr.sup.2+, Ba.sup.2+, Sc.sup.2+, Sc.sup.2+, Sc.sup.+,
Y.sup.3+, Y.sup.2+, Y.sup.+, Ti.sup.+, Ti.sup.3+, Ti.sup.2+,
Zr.sup.4+, Zr.sup.3+, Zr.sup.2+, Hf.sup.4+, Hf.sup.3+, V.sup.5+,
V.sup.4+, V.sup.3+, V.sup.2+, Nb.sup.5+, Nb.sup.4+, Nb.sup.3+,
Nb.sup.2+, Ta.sup.5+, Ta.sup.4+, Ta.sup.3+, Ta.sup.2+, Cr.sup.6+,
Cr.sup.5+, Cr.sup.4+, Cr.sup.3+, Cr.sup.2+, Cr.sup.+, Cr,
Mo.sup.6+, Mo.sup.5+, Mo.sup.4+, Mo.sup.3+, Mo.sup.2+, Mo+, Mo,
W.sup.6+, W.sup.5+, W.sup.4+, W.sup.3+, W.sup.2+, W+, W, Mn.sup.7+,
Mn.sup.6+, Mn.sup.5+, Mn.sup.4+, Mn.sup.3+, Mn.sup.2+, Mn.sup.+,
Re.sup.7+, Re.sup.6+, Re.sup.5+, Re.sup.4+, Re.sup.3+, Re.sup.2+,
Re+, Re, Fe.sup.6+, Fe.sup.4+, Fe.sup.3+, Fe.sup.2+, Fe.sup.+, Fe,
Ru.sup.8+, Ru.sup.7+, Ru.sup.6+, Ru.sup.4+, Ru.sup.3+, Ru.sup.2+,
Os.sup.8+, Os.sup.7+, Os.sup.6+, Os.sup.5+, Os.sup.4+, Os.sup.3+,
Os.sup.2+, Os.sup.+, Os, Co.sup.5+, Co.sup.4+, Co.sup.3+,
Co.sup.2+, Co.sup.+, Rh.sup.6+, Rh.sup.5+, Rh.sup.4+, Rh.sup.3+,
Rh.sup.2+, Rh+, Ir.sup.6+, Ir.sup.5+, Ir.sup.4+, Ir.sup.3+,
Ir.sup.2+, Ir+, Ir, Ni.sup.3+, Ni.sup.2+, Ni+, Ni, Pd.sup.6+,
Pd.sup.4+, Pd.sup.2+, Pd+, Pd, Pt.sup.6+, Pt.sup.5+, Pt.sup.4+,
Pt.sup.3+, Pt.sup.2+, Pt+, Cu.sup.4+, Cu.sup.3+, Cu.sup.2+,
Cu.sup.+, Ag.sup.3+, Ag.sup.2+, Ag+, Au.sup.5+, Au.sup.4+,
Au.sup.3+, Au.sup.2+, Au+, Zn.sup.2+, Zn.sup.+, Cd.sup.2+,
Cd.sup.+, Hg.sup.4+, Hg.sup.2+, Hg.sup.+, B.sup.3+, B.sup.2+,
B.sup.+, Al.sup.3+, Al.sup.2+, Al.sup.+, Ga.sup.3+, Ga.sup.2+,
Ga.sup.+, In.sup.3+, In.sup.2+, In1.sup.+, Tl.sup.3+, Tl.sup.+,
Si.sup.4+, Si.sup.3+, Si.sup.2+, Si.sup.+, Ge.sup.4+, Ge.sup.3+,
Ge.sup.2+, Ge.sup.+, Ge, Sn.sup.4+, Sn.sup.2+, Pb.sup.4+,
Pb.sup.2+, As.sup.5+, As.sup.3+, As.sup.2+, As.sup.+, Sb.sup.5+,
Sb.sup.3+, Bi.sup.5+, Bi.sup.3+, Te.sup.6+, Te.sup.5+, Te.sup.4+,
Te.sup.2+, La.sup.3+, La.sup.2+, Ce.sup.4+, Ce.sup.3+, Ce.sup.2+,
Pr.sup.4+, Pr.sup.3+, Pr.sup.2+, Nd.sup.3+, Nd.sup.2+, Sm.sup.3+,
Sm.sup.2+, Eu.sup.3+, Eu.sup.2+, Gd.sup.3+, Gd.sup.2+, Gd+,
Tb.sup.4+, Tb.sup.3+, Tb.sup.2+, Tb.sup.+, Db.sup.3+, Db.sup.2+,
Ho.sup.3+, Er.sup.3+, Tm.sup.4+, Tm.sup.3+, Tm.sup.2+, Yb.sup.3+,
Yb.sup.2+, Lu.sup.3+, and any combination thereof, along with
corresponding metal salt counter-anions.
[0074] Preparation of MOF Supports
[0075] The preparation of the MOFs in the disclosure can be carried
out in either an aqueous, non-aqueous solvents or in a solvent-free
system. The solvent may be polar or non-polar, or a combination
thereof, as the case may be. The reaction mixture or suspension
comprises a solvent system, linker or moieties, and a metal or a
metal/salt complex. The reaction solution, mixture or suspension
may further contain a templating agent, growth modulator or other
non-linker ligands, catalytically active component or combinations
thereof. The reaction mixture may be heated at an elevated
temperature or maintained at ambient temperature, depending on the
reaction components.
[0076] Examples of non-aqueous solvents that can be used in the
reaction to make the MOF and/or used as non-aqueous solvent for a
post synthesized MOF reaction, include, but is not limited to:
n-hydrocarbon based solvents, such as pentane, hexane, octadecane,
and dodecane; branched and cyclo-hydrocarbon based solvents, such
as cycloheptane, cyclohexane, methyl cyclohexane, cyclohexene,
cyclopentane; aryl and substituted aryl based solvents, such as
benzene, toluene, xylene, chlorobenzene, nitrobenzene,
cyanobenzene, naphthalene, and aniline; mixed hydrocarbon and aryl
based solvents, such as, mixed hexanes, mixed pentanes, naptha, and
petroleum ether; alcohol based solvents, such as, methanol,
ethanol, n-propanol, isopropanol, propylene glycol,
1,3-propanediol, n-butanol, isobutanol, 2-methyl-1-butanol,
tert-butanol, 1,4-butanediol, 2-methyl-1-pentanol, and 2-pentanol;
amide based solvents, such as, dimethylacetamide, dimethylformamide
(DMF), diethylformamide (DEF), formamide, N-methylformamide,
N-methylpyrrolidone, and 2-pyrrolidone; amine based solvents, such
as, piperidine, pyrrolidine, collidine, pyridine, morpholine,
quinoline, ethanolamine, ethylenediamine, and diethylenetriamine;
ester based solvents, such as, butylacetate, sec-butyl acetate,
tert-butyl acetate, diethyl carbonate, ethyl acetate, ethyl
acetoacetate, ethyl lactate, ethylene carbonate, hexyl acetate,
isobutyl acetate, isopropyl acetate, methyl acetate, propyl
acetate, and propylene carbonate; ether based solvents, such as,
di-tert-butyl ether, diethyl ether, diglyme, diisopropyl ether,
1,4-dioxane, 2-methyltetrahydrofuran, tetrahydrofuran (THF), and
tetrahydropyran; glycol ether based solvents, such as,
2-butoxyethanol, dimethoxyethane, 2-ethoxyethanol,
2-(2-ethoxyethoxy)ethanol, and 2-methoxyethanol; halogenated based
solvents, such as, carbon tetrachloride, chlorobenzene, chloroform,
1,1-dichloroethane, 1,2-dichloroethane, 1,2-dichloroethene,
dichloromethane (DCM), diiodomethane, epichlorohydrin,
hexachlorobutadiene, hexafluoro-2-propanol, perfluorodecalin,
perfluorohexane, tetrabromomethane, 1,1,2,2-tetrachloroethane,
tetrachloroethylene, 1,3,5-trichlorobenzene, 1,1,1-trichloroethane,
1,1,2-trichloroethane, trichloroethylene, 1,2,3-trichloropropane,
trifluoroacetic acid, and 2,2,2-trifluoroethanol; inorganic based
solvents, such as hydrogen chloride, ammonia, carbon disulfide,
thionyl chloride, and phosphorous tribromide; ketone based
solvents, such as, acetone, butanone, ethylisopropyl ketone,
isophorone, methyl isobutyl ketone, methyl isopropyl ketone, and
3-pentanone; nitro and nitrile based solvents, such as,
nitroethane, acetonitrile, and nitromethane; sulfur based solvents,
dimethyl sulfoxide (DMSO), methylsulfonylmethane, sulfolane,
isocyanomethane, thiophene, and thiodiglycol; urea, lactone and
carbonate based solvents, such as
1-3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone (DMPU),
1-3-dimethyl-2-imidazolidinone, butyrolactone, cis-2,3-butylene
carbonate, trans-2,3-butylene carbonate, 2,3-butylene carbonate;
green solvents such as cyrene and valerolactone; ionic liquids;
carboxylic acid based solvents, such as formic acid, acetic acid,
chloracetic acid, trichloroacetic acid, trifluoroacetic acid,
propanoic acid, butanoic acid, caproic acid, oxalic acid, and
benzoic acid; boron and phosphorous based solvents, such as
triethyl borate, triethyl phosphate, trimethyl borate, and
trimethyl phosphate; deuterium containing solvents, such as
deuterated acetone, deuterated benzene, deuterated chloroform,
deuterated dichloromethane, deuterated DMF, deuterated DMSO,
deuterated ethanol, deuterated methanol, and deuterated THF; and
any appropriate mixtures thereof.
[0077] In another embodiment, the nonaqueous solvent used as the
solvent system in synthesizing the MOF has a pH less than 7. In a
further embodiment, the solvent system used to synthesize the MOF
is an aqueous solution that has a pH less than 7. In yet a further
embodiment, the solvent system used to synthesize the frameworks
contains water. In another embodiment, the solvent system used to
synthesize the frameworks contains water and hydrochloric acid.
[0078] Those skilled in the art will be readily able to determine
an appropriate solvent or appropriate mixture of solvents based on
the starting reactants and/or where the choice of a particular
solvent(s) is not believed to be crucial in obtaining the materials
of the disclosure.
[0079] In a certain embodiment, crystallization of the frameworks
can be improved by adding an additive that promotes nucleation.
[0080] In a certain embodiment, the solution, mixture or suspension
is maintained at ambient temperature to allow for crystallization.
In another embodiment, the solution, mixture, or suspension is
heated in isothermal oven for up to 300.degree. C. to allow for
crystallization. In yet another embodiment, activated frameworks
can be generated by calcination. In a further embodiment,
calcination of the frameworks can be achieved by heating the
frameworks at 350.degree. C. for at least 1 hour.
[0081] In a certain embodiment, the MOF is synthesized in a
solvent-free system through mechanical mixing such as ball milling
or grinding of the reaction mixture comprised of the linker or
moieties, and a metal or a metal/salt complex. The reaction mixture
may further contain a templating agent, growth modulator or other
non-linker ligands, catalytic active component or combinations
thereof. The reaction mixture may be heated at an elevated
temperature or maintained at ambient temperature, depending on the
reaction components.
[0082] After the MOFs are synthesized, the MOFs may be further
modified by reacting with one or more post MOF reactants that may
or may not have denticity. In a certain embodiment, the frameworks
as-synthesized are not reacted with a post framework reactant. In
another embodiment, the frameworks as-synthesized are reacted with
at least one post framework reactant. In yet another embodiment,
the frameworks as-synthesized are reacted with at least two post
framework reactants. In a further embodiment, the frameworks
as-synthesized are reacted with at least one post framework
reactant that will result in adding denticity to the framework.
[0083] It is contemplated by this disclosure that chemical
reactions that modify, substitute, or eliminate a functional group
post-synthesis of the MOF with post framework reactant may use one
or more similar or divergent chemical reaction mechanisms depending
on the type of functional group and/or post framework reactant used
in the reaction. Examples of chemical reaction mechanisms
contemplated by this arrangement include, but is not limited to,
radical-based, unimolecular nucleophilic substitution (SN1),
bimolecular nucleophilic substitution (SN2), unimolecular
elimination (E1), bimolecular elimination (E2), E1cB elimination,
nucleophilic aromatic substitution (SnAr), nucleophilic internal
substitution (SNi), nucleophilic addition, electrophilic addition,
oxidation, reduction, cycloaddition, ring closing metathesis (RCM),
pericylic, electrocylic, rearrangement, carbene, carbenoid, cross
coupling, and degradation.
[0084] It is yet further contemplated by this disclosure that to
enhance chemoselectivity, it may be desirable to protect one or
more functional groups that can generate unfavorable products upon
a chemical reaction desired for another functional group, and then
deprotect this protected group after the desired reaction is
completed. Employing such a protection/deprotection strategy could
be used for one or more functional groups.
[0085] Other agents can be added to increase the rate of the MOF
formation reactions disclosed herein, including adding catalysts,
bases, and acids.
[0086] In another embodiment, the post framework reactant is
selected to have a property selected from the group comprising,
binds a metal ion, increases the hydrophobicity of the framework,
decreases the hydrophobicity of the framework, modifies the
chemical sorption of the framework, modifies the pore size of the
framework, and tethers a catalyst to the framework.
[0087] In one embodiment, the post framework reactant can be a
saturated or unsaturated heterocycle.
[0088] In another embodiment, the post framework reactant has 1-100
atoms with functional groups including atoms such as N, S, O, P and
transition metals.
[0089] In yet another embodiment, the post framework reactant is
selected to modulate the size of the pores in the framework.
[0090] In another embodiment, the post framework reactant is
selected to increase the hydrophobicity of the framework. In an
alternative embodiment, the post framework reactant is selected to
decrease the hydrophobicity of the framework.
[0091] In yet another embodiment, the post framework reactant is
selected to modulate chemical, inorganic and/or organic sorption of
the framework.
[0092] In yet another embodiment, the post framework reactant is
selected to modulate gas separation of the framework. In a certain
embodiment, the post framework reactant creates an electric dipole
moment on the surface of the framework when it chelates a metal
ion.
[0093] In a further embodiment, the post framework reactant is
selected to modulate the gas sorption properties of the framework.
In another embodiment, the post framework reactant is selected to
promote or increase hydrocarbon gas sorption of the framework.
[0094] In yet a further embodiment, the post framework reactant is
selected to increase or add catalytic efficiency to the
framework.
[0095] In another embodiment, a post framework reactant is selected
so that organometallic complexes can be tethered to the framework.
Such tethered organometallic complexes can be used, for example, as
heterogeneous catalysts.
[0096] To improve MOF catalyst usage the following are possible
ways to improve the MOF and or determine the best possible MOF
support to utilize. The organic linkers and nodes could be selected
to achieve MOFs with large pore size and improve the diffusion of
reactants and reagents through the MOF catalyst, improving catalyst
life. Growth modulators could be used to create defects in the MOF
structure to also improve diffusion and catalyst life. Synthetic
modification of the organic linker could be done to increase the
hydrophobicity of the MOF. This increases the local concentration
of desired reactant molecules around the acid sites and optimize
catalyst selectivity. Aside from the MOF nodes and linkers,
non-linker ligands could be used as attachment points for acid
sites, which expands the types of MOF supports that could be used
to make the acid MOF catalysts. It is envisioned that by using some
or all of the parameters above one can be able to select MOFs for
improved alkylation and/or oligomerization catalytic activity.
EXAMPLES OF MOFS
[0097] The following additional examples of certain embodiments of
the invention are given. Each example is provided by way of
explanation of the invention, one of many embodiments of the
invention, and the following examples should not be read to limit,
or define, the scope of the invention.
[0098] Table 1 below lists some exemplary MOFs that are currently
used
TABLE-US-00001 TABLE 1 Chanel Pore Name Nodecomp. Topology Type
Size (.ANG.) HKUST-1 Cu tbo 3D 12 MIL-101 Al, Fe, Cr mtm 3D 16, 29,
34 UiO-66 Zr, Hf, Ce fcu 3D 8 UiO-67 Zr, Hf fcu 3D 12 MOF-808 Zr,
Hf, Ce spn 3D 16 PCN-777 Zr, Hf spn 3D 32 PCN-224 Zr, Hf she 1D 20
PCN-222 Zr, Hf csq 1D 37 NU-1000 Zr, Hf csq 1D 31
[0099] The linkers currently used to build MOFs are shown in FIG.
1.
[0100] Non-limiting examples of ways to create acid sites in MOFs
include the functionalization of metal nodes with oxyanions,
encapsulating heteropolyacids on the MOFs, grafting sulfonic acids
on the MOFs, or even immobilization of ionic liquids on MOFs. It is
expected that individual physical tests can be run to determine the
best MOFs for catalytic applications.
[0101] These acid MOFs can then be tested differently using methods
such as: Oligomerization testing (for oligomerization activity and
long term stability), Alkylation testing (for cracking activity,
oligomerization activity, alkylation performance and stability),
and Batch Reactor Testing (Testing for activity for isomerization,
activity for alkylation and activity hydride transfer).
Example 1
[0102] Ionic Liquids in MOFs
[0103] For MOF-supported Ionic Liquids (ILs), the anchor point
could be the metal node or a functional group on the linker. ILs
are salts with a low melting point, typically less than 100.degree.
C. The origin of the low melting point is the charge delocalization
in its bulky constituent ions, leading to small lattice enthalpies
and large entropy changes that favor melting. The variety of
choices for cations and anions provides a high synthetic
flexibility for ILs, and this flexibility is magnified by the
ability to make IL mixtures.
[0104] ILs can display Lewis or Bronsted acidity or both. Most of
the known Lewis acidity comes from the electron-pair-accePting
ability of the anion, while Bronsted acidity can come from the
cation and/or the anion. Additional Bronsted sites such as
--SO.sub.3H can also be introduced through alkyl side chains
tethered to the ionic core.
[0105] For alkylation, ILs containing multinuclear halometallate
anions such as [Al.sub.2Cl.sub.7].sup.- are highly active and are
thus among the synthetic targets for MOF-based alkylation catalyst
in this invention.
Example 2
[0106] MOF-Supported Heteropolyacids
[0107] Heteropolyacids (HPAs), specifically phosphotungstic acid
(PTA), had been encapsulated in MOF pores. MOFs used to host
H.sub.3PW.sub.12O.sub.40 include MIL-100, MIL-101, UiO-67, NU-1000,
HKUST-1, ZIF-67 and ZIF-8. HPAs are solid acids that incorporate
transition metal-oxygen clusters as anions. They are called the
Keggin and Wells-Dawson structures, and like other HPA anions, they
feature metal-oxygen octahedra as a basic structural unit. The most
common metals that make up the octahedra are tungsten, molybdenum,
and vanadium. The anion is formed when these octahedra surround one
or more heteroatoms, which are often phosphorous or silicon. The
acidity of HPAs is purely Bronsted in nature. For the commercially
available Keggin-type HPAs, the acid strength decreases in the
order H3PW12O40>H4SiW12O40>H3PMo12O40>H4SiMo12O40.
H3PW12O40 (called phosphotungstic acid, hereon referred to as PTA)
was found to be more acidic than H2SO4 and is therefore a suitable
acid site candidate to make acid MOF catalysts.
[0108] With MIL-101, the PTA loading could be as high as 60% by
weight. The synthesis is also facile. PTA can be added to the MOF
synthesis mixture in a one-pot type ship-around-bottle synthesis or
it can be impregnated into the MOF post-synthesis. A common concern
with supported PTA is the strong interaction between PTA and
traditional supports like silica, which lowers the acidity of the
former. The nature of the MOF building blocks gives it different
surface properties, which can be tuned to minimize any effects on
the acidity of encapsulated PTA
[0109] In one embodiment, a metal organic framework composition can
comprise a solid metal organic framework supported heteropolyacid
wherein the heteropolyacid loading is greater than 25% by weight
and the pore volume is less than 2 mL/g. In one non-limiting
embodiment, the composition can be formed by forming a solution
containing a heteropolyacid and a solvent to form a heteropolyacid
solution, soaking a metal organic framework in the heteropolyacid
solution to form an impregnated metal organic framework, and drying
the impregnated metal organic framework to form a solid metal
organic framework supported heteropolyacid. In another non-limiting
embodiment, the composition can be formed by mixing a solution of
solid metal organic framework starting reagents and a
heteropolyacid to form a starting solution and reacting the
starting solution in a reactor to form a solid metal organic
framework supported heteropolyacid.
[0110] In one non-limiting embodiment, the pore volume of the solid
metal organic framework supported heteropolyacid is less than 2
mL/g. In another non-limiting embodiment, the BET surface area of
the solid metal organic framework supported heteropolyacid is less
than 4,500 m.sup.2/g.
[0111] Non-limiting examples of HPAs include
H.sub.3PW.sub.12O.sub.40, H.sub.3PMo.sub.12O40,
H.sub.3SiW.sub.12O.sub.40, H.sub.6P.sub.2Mo.sub.18O.sub.62.
[0112] The process of a reaction can be a heterogenous reaction
between a solid metal organic framework supported heteropolyacid
catalyst and a hydrocarbon feed. This modified hydrocarbon stream
can comprise essentially of C.sub.6+ hydrocarbons.
[0113] Preparation of HPA Materials:
[0114] PTA. The reference PTA catalyst was prepared heat-treating
phosphotungstic acid hydrate at 300.degree. C. to dehydrate the
sample prior to catalyst testing.
[0115] Silica-supported PTA catalyst (PTA@SiO.sub.2). This
reference catalyst was prepared via solution impregnation. Silica
gel was immersed in a solution of PTA in H.sub.2O. The solid was
separated by filtration and dried in a vacuum oven.
[0116] MIL-101. The MIL-101 MOF used as support for PTA was
synthesized by dissolving Cr(NO.sub.3).sub.3.9H.sub.2O in an
aqueous solution of HNO.sub.3. Terephthalic acid was then added.
The MOF synthesis was then carried out in a Parr reactor at a
suitable temperature for MOF formation. The product, MIL-101, was
washed with H.sub.2O and ethanol prior to air-drying.
[0117] MIL-101-supported PTA prepared via solution impregnation.
Two samples were prepared as follows: (1) A solution of PTA in
H.sub.2O was first prepared. MIL-101 was immersed in this solution.
The solid was separated by centrifugation, air-dried and then dried
in an oven. This sample is denoted as imp-PTA@MIL-101. (2) The
second sample was prepared using the same procedure as (1), excePt
the pH of the PTA solution was adjusted by using an aqueous
solution of HNO.sub.3. This sample is denoted as
imp-PTA@MIL-101-pH.
[0118] MIL-101-supported PTA prepared via one-pot synthesis. Two
samples with different PTA loadings were prepared. The same
synthesis as MIL-101 was followed except PTA was dissolved in the
reaction mixture prior to loading into the Parr reactor. Different
PTA loadings were achieved by varying the amount of PTA added to
the MIL-101 reaction mixture. The samples are denoted as
op-PTA@MIL-101 and op-PTA@MIL-101-low, for the normal and lower
loading samples, respectively.
[0119] Characterization of HPA Materials
[0120] The PTA loading and textural properties of the supported PTA
samples were determined by XRF and N.sub.2 physisorption analyses,
respectively. Please see Table 2
TABLE-US-00002 TABLE 2 Weight % BET Pore PTA Surface Area Volume
Material Type Material from XRF (m2/g) (mL/g) Support silica gel --
474 0.91 MIL-101 -- 3030 1.34 Silica gel-supported PTA
PTA@SiO.sub.2 30 389 0.74 via wet impregnation MIL-101-supported
PTA imp-PTA@MIL-101 62 711 0.34 via wet impregnation
imp-PTA@MIL-101-pH 63 821 0.38 MIL-101-supported PTA op-PTA@MIL-101
65 720 0.35 via one-pot synthesis op-PTA@MIL-101-low 34 1963
0.93
[0121] The PTA loading for the reference PTA@SiO.sub.2 sample was
30%, which is enough to disperse a monolayer of PTA on the surface
of the silica support. High PTA loadings in MIL-101 (34 to 65% by
weight) were achieved.
[0122] Different analysis such as XRD and IR spectroscopy were
carried out. The XRD patterns of the MIL-101 supported PTA samples
compared to pure PTA and MIL-101 are shown in FIG. 2. The IR
spectroscopy of the samples are shown in FIG. 3.
[0123] Catalytic Tests for HPA Materials--Alkylation
[0124] PTA and the supported PTA samples were evaluated for both
liquid-phase and supercritical-phase alkylation of isobutane and
trans-2-butene. All reactions were carried out in a fixed-bed
reactor. Reactor effluents were analyzed by an on-line GC using an
FID detector. The samples were screened by loading the catalyst
into the reactor and testing at the same activation and run
temperatures, and isobutane-to-olefin of the feed. All samples were
activated in situ at pre-selected temperatures under a flow of
N.sub.2. Bare PTA samples were also dehydrated in a furnace to
remove most of the water of hydration prior to loading into the
reactor. Fresh catalyst was used for each run.
[0125] Results from the isobutane/trans-2-butene alkylation tests
using PTA and PTA@SiO.sub.2 catalysts are shown in FIG. 4 and FIGS.
5a and 5b.
[0126] FIG. 4 depicts alkylation results of showing trans-2-butene
conversion and C8 paraffin selectivity versus catalyst age for PTA.
Test conditions for FIG. 4 were: activation temperature=225.degree.
C., reaction temperature=room temperature, isobutane-to-olefin
ratio=15, WHSV=0.12 h-1.
[0127] FIG. 5a depicts conversion v. catalyst age alkylation
results and FIG. 5b depicts C8 selectivity v. conversion % under
different test conditions for PTA@SiO.sub.2. The legend indicates
the activation temperature (act), reaction temperature (rxn),
isobutane-to-olefin ratio (I/O) and weight hourly space velocity
(WHSV) for each test.
[0128] FIG. 6a depicts conversion v. catalyst age alkylation
results and FIG. 6b depicts C8 selectivity v. conversion % for
op-PTA@MIL-101 samples with results for PTA@SiO2 tested under
similar WHSV are included for comparison. Test conditions for FIG.
6a and FIG. 6b were: activation temperature=225.degree. C.,
reaction temperature=room temperature, reaction pressure=300 psi
and isobutane-to-olefin I/O=15.
[0129] FIG. 7a depicts conversion v. catalyst age alkylation
results and FIG. 7b depicts C8 selectivity v. conversion % depicts
alkylation results for imp-PTA@MIL-101 samples with results for
PTA@SiO2 tested under similar WHSV are included for comparison.
Test conditions for FIG. 7a and FIG. 7b were: activation
temperature=225.degree. C., reaction temperature=room temperature,
reaction pressure=300 psi and isobutane-to-olefin I/O=15.
[0130] FIG. 8a and FIG. 8b depicts the supercritical alkylation
using PTA@SiO.sub.2 and imp-PTA@MIL-101-pH as catalyst. Test
conditions for FIG. 8a and FIG. 8b were: activation
temperature=225.degree. C., reaction temperature=137.degree. C.,
reaction pressure=653 psig and isobutane-to-olefin I/O=33.25.
[0131] FIG. 9 depicts the activity in a batch reactor for
imp-PTA@MIL-101 for the oligomerization of isobutene,
trans-2-butene and propylene in terms of conversion versus
time.
[0132] FIG. 10 depicts the product selectivity of imp-PTA@MIL-101
for the oligomerization of isobutene, trans-2-butene and propylene
in a batch reactor.
Example 3
[0133] Sulfonic Acid-Functionalized MOFs
[0134] Catalysts bearing perfluorinated sulfonic acid groups have
high acid strength. A well-known example is Nafion, which had been
reported in literature as an alkylation catalyst. In this
invention, solid acid catalysts comprised of MOFs bearing
halogenated and non-halogenated alkyl- and arylsulfonic acid sites
are targeted.
[0135] The solid acid catalysts disclosed in this example are MOFs
functionalized with halogenated and non-halogenated alkyl and aryl
sulfonic acids. The functionalized MOF is prepared by a reaction
between the nucleophilic groups present in the MOF's building units
and cyclic sulfonate esters called sultones. Such reaction can
yield sulfonic acids in the MOF's internal surface. These MOFs may
be used as acid catalysts, even for those reactions that require
high acid strength such as isoparaffin-olefin alkylations. Using
perflourinated sultones can yield perfluorosulfonic acid sites on
the MOFs, reminiscent of the highly acidic sites found in Nafion,
and thus yielding an acid MOF catalyst that is a suitable candidate
for alkylation catalysis.
[0136] FIG. 11 shows the reaction scheme for the condensation
between a MOF hydroxyl and a sultone. FIG. 12 shows examples of MOF
building units bearing such nucleophilic functionalities such as
amino- and hydroxyl groups. FIG. 13 shows examples of MOF ligands
bearing such nucleophile functionalities such as amino and hydroxyl
groups.
[0137] Sultones that can be used for this synthesis include, but
are not limited to, the examples shown in FIG. 14.
[0138] In one embodiment, the solid metal-organic framework
composition can comprise a solid metal-organic framework supported
sulfonic acid wherein the sulfur content is greater than 0.5
mmol/gram. The composition of solid metal organic framework
supported sulfonic acid can be made by reacting the metal organic
framework with sultones in solution at temperatures ranging from
25.degree. C. to 200.degree. C. to form the sulfonic
acid-functionalized metal organic framework. The functionalized
metal organic framework is dried to obtain the solid metal organic
framework supported sulfonic acid. In one embodiment the reaction
of the metal organic framework with the sultone occurs without any
external applied heat.
[0139] Alternatively, perfluorinated sulfonic acid sites can be
generated in MOFs using multifunctional organic molecules, where
one functionality is the perfluorinated sulfonic acid group and the
other is a binding motif for the metal organic framework such as,
but not limited to, a carboxylate or another sulfonic acid
group.
[0140] The process of a reaction can be a heterogenous reaction
between a solid metal organic framework supported sulfonic acid and
a hydrocarbon feed. This modified hydrocarbon stream can comprise
essentially of C.sub.6+ hydrocarbons.
[0141] Preparation of Sulfonic Acid-Functionalized MOFs
[0142] MOF-808. MOF-808 was synthesized by dissolving
ZrOCl.sub.2.8H.sub.2O in formic acid. 1,3,5-benzenetricarboxylic
acid was also dissolved in anhydrous DMF to create a separate
solution. The two solutions were mixed, allowed to react under
suitable conditions to form the MOF, and the solids were extracted.
The solids were then treated with HCl. Finally, the solids were
washed, air-dried and then heat-treated.
[0143] Hf-MOF-808. Hf-MOF-808 was prepared in the same manner as
MOF-808, except using HfCl.sub.4 instead of ZrOCl.sub.2.8H.sub.2O
as metal precursor for the synthesis.
[0144] MIL-101. MIL-101 was synthesized by dissolving
Cr(NO.sub.3).sub.3.9H.sub.2O in an aqueous solution of HNO.sub.3.
Terephthalic acid was then added and reacted in a heated reactor.
The product was then extracted and heat treated.
[0145] Sulfonic Acid Functionalization of MOF Supports. Sulfonic
acid sites were incorporated in MOFs by refluxing the MOFs in a
toluene solution of the desired sultone under inert atmosphere.
After the reaction mixture is cooled down to room temperature, the
solids were washed and dried to obtain the solid sulfonic
acid-functionalized MOFs.
[0146] Properties:
[0147] Both MOF and silica supports were functionalized with
sulfonic acids to demonstrate the different sulfur content in the
sultone grafted product. Table 3 depicts the results
TABLE-US-00003 TABLE 3 Sulfonic acid to MOF Node S content in Ratio
in MOF grafted product Support Sultone Sample Name Product (mmol/g)
MOF-808 1,4-butane sultone C.sub.4H.sub.8SO.sub.3H@MOF-808 3.6 2.09
MIL-101 C.sub.4H.sub.8SO.sub.3H@MIL-101 1.1 1.47 MOF-808
hexafluoro(3- C.sub.3F.sub.6SO.sub.3H@MOF-808 2.3 1.85 Hf-MOF-808
methyl-1,2- C.sub.3F.sub.6SO.sub.3H@Hf-MOF-808 1.7 0.83 Commercial
oxathietane)-2,2- C.sub.3F.sub.6SO.sub.3H@SBA-15 N/A 0.17 Silica
dioxide Sample A Commercial C.sub.3F.sub.6SO.sub.3H@MCM-41 N/A 0.28
Silica Sample B MOF-808 1-(nonafluorobutyl)
C.sub.6F.sub.12SO.sub.3H@MOF-808 1.2 1.07 trifluoroethane
sultone
[0148] Catalytic Tests for Sulfonic Acid-Functionalized
MOFs--Alkylation
[0149] Samples were evaluated for both liquid-phase and
supercritical-phase alkylation of isobutane and trans-2-butene. All
reactions were carried out in a fixed-bed reactor. Reactor
effluents were analyzed by an on-line GC using an FID detector. The
samples were screened by loading the catalyst into the reactor and
testing at the same activation and run temperatures, and
isobutane-to-olefin of the feed. All samples were activated in situ
at pre-selected temperatures under a flow of Na. Fresh catalyst was
used for each run.
[0150] Two methods were used to for the regeneration of the
partially deactivated catalyst bed. One is by heating under
N.sub.2. The second method was supercritical isobutane regeneration
at temperatures and pressures above the supercritical point for
isobutane.
[0151] FIG. 15, FIG. 16, and FIG. 17 depict the liquid-phase
alkylation of isobutane with trans-2-butene using different
sulfonic acid-decorated MOF catalysts.
[0152] FIG. 15 depicts alkylation results for
C.sub.3F.sub.6SO.sub.3H@MOF-808 catalyst samples. Test conditions
for FIG. 15 were: reaction temperature=80.degree. C., reaction
pressure=300 psi and isobutane-to-trans-2-butene ratio I/O=134, and
weight hourly space velocity of 0.12 h.sup.-1. The sulfonic acid to
MOF node ratio in the product was 1.5 with a S content in the
sultone grated product of 1.97 mmol/g.
[0153] FIG. 16 depicts alkylation results for
C.sub.6F.sub.12SO.sub.3H@MOF-808 catalyst samples. Test conditions
for FIG. 16 were: reaction temperature=80.degree. C., reaction
pressure=300 psi and isobutane-to-trans-2-butene ratio I/O=134, and
weight hourly space velocity of 0.12 h.sup.-1. The sultone to MOF
node ratio in the product was 1.2 with a S content in the sultone
grated product of 1.07 mmol/g.
[0154] FIG. 17 depicts alkylation results for
C.sub.3F.sub.6SO.sub.3H@Hf-MOF-808 catalyst samples. Test
conditions for FIG. 17 were: reaction temperature=80.degree. C.,
reaction pressure=300 psi and isobutane-to-trans-2-butene ratio
I/O=128, and weight hourly space velocity of 0.10 h.sup.-1. The
sulfonic acid to MOF node ratio in the product was 1.7 with a S
content in the sultone grated product of 0.83 mmol/g.
[0155] FIG. 18 depicts the supercritical alkylation of isobutane
and trans-2-butene with a sulfonic acid-decorated MOF
(C.sub.3F.sub.6SO.sub.3H@MOF-808). Test conditions for FIG. 18
were: reaction temperature=137.degree. C., reaction pressure=635
psi and isobutane-to-trans-2-butene ratio I/O=134, and weight
hourly space velocity of 0.07 h.sup.-1. The sultone to MOF node
ratio in the product was 2.34 with a S content in the sultone
grated product of 1.85 mmol/g.
[0156] FIG. 19 depicts the alkylation results for C3F6SO3H@MOF-808
catalyst samples. Test results for FIG. 19 were: reaction
temperature=80.degree. C., reaction pressure=300 psi and
isobutane-to-olefin ratio I/O=76, and weight hourly space velocity
of 0.13 h.sup.-1.
[0157] FIG. 20 depicts alkylation results for
C.sub.3F.sub.6SO.sub.3H@MOF-808 catalyst with supercritical
isobutane regeneration. In supercritical isobutane regeneration the
feed is switched from the reaction mixture to pure isobutane to
stop the alkylation step. After flushing with isobutane for 30 min,
the reactor temperature was increased to 137.degree. C. and the
pressure to 653 psi. Supercritical isobutane regeneration was
carried out for 4 h at a WHSV of 33 h.sup.-1. After the
regeneration step was completed, the reactor is brought back to the
reaction temperature and pressure, and the flow of the reaction
mixture was started for the next alkylation step. Test results for
FIG. 20 were: reaction temperature=80.degree. C., reaction
pressure=300 psi and isobutane-to-olefin ratio I/O=134, and weight
hourly space velocity of 33 h.sup.-1.
[0158] FIG. 21 depicts alkylation results for
C.sub.3F.sub.6SO.sub.3H@MOF-808 catalyst with regeneration under
N.sub.2 flow. In regeneration under N.sub.2 flow after stopping the
reaction mixture flow, the reactor is flushed for 30 min with a 50
mL/min flow of N.sub.2. The reactor temperature was then increased
to 110.degree. C. and the pressure dropped to atmospheric. After 12
h of regeneration, the reactor is brought back to the reaction
temperature and pressure, filled throughout with isobutane and the
flow of the reaction mixture was started for the next alkylation
step. FIG. 21 were: reaction temperature=80.degree. C., reaction
pressure=300 psi and isobutane-to-olefin ratio I/O=134, and weight
hourly space velocity of 0.15 h.sup.-1.
[0159] The product distribution from the alkylation of isobutane
with trans-2-butene catalyzed by a perfluorinated sulfonic
acid-functionalized MOF (C.sub.3F.sub.6SO.sub.3H@MOF-808) is shown
in Table 4. Reaction conditions: temperature=80.degree. C.,
pressure=300 psi, and weight hourly space velocity (WHSV)=0.13
h.sup.-1. The production of C8 paraffins indicates that this acid
MOF is capable of catalyzing the alkylation reaction of isobutane
with trans-2-butene. TMP is trimethylpentane, and DMH is
dimethylhexane.
TABLE-US-00004 TABLE 4 TOS (min) 35 Olefin Conversion (%) 87
C.sub.5+ product distribution (%) C.sub.5-C.sub.7 14 C.sub.8 41
C.sub.8= 20 C.sub.9+ 25 C.sub.8 product distribution (%) 2,2,4-TMP
11 2,2,3-TMP 1 2,3,4-TMP 20 2,3,3-TMP 12 DMHs 56
[0160] Catalytic Tests for Sulfonic Acid-Functionalized
MOFs--Oligomerization
[0161] Oligomerization catalytic testing was performed in a
pressurized batch reactor. The catalyst was pre-treated using
vacuum and heat. Then the reactor was pressurized with the desired
olefin. The pressure and temperature were monitored and was used to
calculate conversion. At the end of the run a gas sample was
collected and analyzed by gas chromatography to determine the
product distribution.
[0162] We describe of using sulfonic acid functionalized-MOF-808 to
oligomerize isobutane (iC.sub.4), propylene (C.sub.3), and
trans-2-butylene(t2b). The activity is compared to MOF-808
SO.sub.4.
[0163] FIG. 22 depicts the results of the oligomerization reaction
over the various sulfonic acid-functionalized MOF-808 materials
over time. MOF-808-SO.sub.4, described in the next Example, was
included in the plot as a reference.
[0164] FIG. 23 depicts the product selectivity for the
oligomerization reaction over the various sulfonic
acid-functionalized MOF-808 materials over time. MOF-808-SO.sub.4,
described in the next Example, was included in the plot as a
reference.
Example 4
[0165] Oxyanion-Modified Metal Organic Frameworks
[0166] In one example a superacidic MOF can be sulfated into
MOF-808. This MOF analogue of sulfated zirconia (SZ) is prepared by
immersing MOF-808 in dilute H.sub.2SO.sub.4, resulting in adsorbed
sulfates on the MOF's zirconium oxocluster node. The sulfated node
(.about.0.5 nm in size) can be considered a nano-sized SZ.
[0167] In this example we describe a process that uses an acidic
MOF that can selectively oligomerize light olefins
(C.sub.3-C.sub.6) to more valuable, heavier products (high octane
gasoline, low sulfur diesel, jet fuel, specialty solvents or
synthetic lube oils) which have been forecast to have great growth
potential despite the forecasted changes in gasoline demand. As an
example of how this process might be applied a MOF capable of
reacting only with isobutene can be used to upgrade a mixed C.sub.4
olefin feed into to a more valuable C.sub.12 and C.sub.8 olefin
stream.
[0168] MOFs can also be made with different metals as nodes and
different acid site functionalities. As described above the metal
ion nodes could be composed of one or more metal ions from Group 1
through 16 of the IUPAC Periodic Table of the Elements including
actinides, and lanthanides, and combinations thereof.
[0169] The loading of the metals on the nodes can be 1 atom per
node, 2 atoms per node, 3 atoms per node, 4 atoms per node, 5 atoms
per node, 6 atoms per node, 7 atoms per node, or even 8 atoms per
node or more. In one non-limiting example oxygen can be loaded onto
the solid metal organic framework from 1 atom per node, 10 atoms
per node, 20 atoms per node, or even 25 atoms per node and
greater.
[0170] The composition of an oxyanion-modified metal organic
framework can be made by mixing a previously prepared solid
metal-organic framework and a solution of suitable concentration of
the desired oxyanion in either aqueous or organic media. The
resulting suspension is allowed to react and equilibrate over a
suitable period of time. The solid can then be then recovered,
washed and dried to form an oxyanion-modified metal organic
framework.
[0171] The process of a reaction can be a heterogenous reaction
between a solid oxyanion-modified metal organic framework and a
hydrocarbon feed. This modified hydrocarbon stream can comprise
essentially of C.sub.6+ hydrocarbons.
Oxyanion-Modified Metal Organic Frameworks Examples
[0172] Zr-MOF-808 Base material. A solution of zirconium
oxychloride and formic acid in DMF was combined with a solution of
BTC linker in DMF. The solution was placed in an oven and heated to
a suitable temperature for the formation of the MOF structure. The
MOF precipitate was collected by centrifugation and washed with of
fresh solvent and heat treated to yield activated sample.
[0173] Hf-MOF-808 Base material. A solution of hafnium oxychloride
and formic acid in DMF was combined with a solution of BTC linker
in DMF. The solution was placed in an oven and heated to a suitable
temperature for the formation of the MOF structure. The MOF
precipitate was collected by centrifugation and washed with of
fresh solvent and heat treated to yield activated sample.
[0174] Ce-MOF-808 Base material. A solution of cerium ammonium
nitrate and formic acid in DMF was combined with a solution of BTC
linker in DMF. The solution was placed in an oven and heated to a
suitable temperature for the formation of the MOF structure. The
MOF precipitate was collected by centrifugation and washed with of
fresh solvent and heat treated to yield activated sample.
[0175] Example of an oxyanion-modified metal-organic framework:
Zr-MOF-808-SO.sub.4. Zr-MOF-808 was immersed in a solution of
sulfuric acid. The mixture was allowed to react for a suitable
amount of time and the solids were collected. The modified MOF can
be washed and heat treated to yield the activated sample.
[0176] Properties:
[0177] Table 5 below depicts the energy dispersive X-ray
spectroscopy data of element distribution and relative composition
of a samples surface.
TABLE-US-00005 TABLE 5 Zr-MOF-808-SO4 Element C O S Zr Hf Atomic %
55.7 35.7 1.7 6.7 0.1 Atoms/node 49.8 32.0 1.5 6.0 0.1
Zr-MOF-808-PO4 Element C O P Zr Hf Atomic % 59.2 32.4 0.3 6.8 0.1
Atoms/node 52.5 28.8 0.3 6.0 0.1 Hf-MOF-808-SO4 Element C O S Hf
Atomic % 51.8 37.2 2.8 8.2 Atoms/node 38.0 27.3 2.1 6.0
Hf-MOF-808-PO4 Element C O P Hf Atomic % 52.9 38.1 0.1 8.9
Atoms/node 35.7 25.7 0.0 6.0 Ce-MOF-808-SO4 Element C O S Ce Atomic
% 55.8 35.5 0.6 8.1 Atoms/node 41.3 26.3 0.4 6.0 Ce-MOF-808-PO4
Element C O P Ce Atomic % 56.6 35.3 0.0 8.1 Atoms/node 41.8 26.1
0.0 6.0
[0178] Catalytic Tests for Oxyanion-Modified Metal-Organic
Frameworks--Oligomerization
[0179] Catalytic testing procedure: a plug-flow reactor was loaded
with oxyanion-modified metal-organic framework mixed with a
diluent. Prior to testing the catalyst was heat treated overnight
under a flow of nitrogen. The reactor was pressurized using an
inert reagent such as isobutane prior to flowing the feed. The
temperature was controlled using a clam furnace. Flow of premixed
isobutene/isobutane feed was achieved via a pump at a suitable rate
for the appropriate time. See FIG. 24 for an example of conversion
as a function of time on stream.
[0180] Additional testing of the Zr-MOF-808-504 catalyst in the
plug-flow reactor for over 300 hours is shown in FIG. 25 wherein
the MOF material is capable of achieving high conversion without
deactivation for long periods of time. It is theorized that, the
MOF architecture allows for C.sub.8 and C.sub.12 product to
evacuate the channels and pores of the catalyst without being
permanently trapped due to the high surface area and large pore
size of the material.
[0181] As shown in FIG. 26, this process utilizes a fixed-bed
reactor which contains a bed of MOF material to convert a stream of
mixed isobutene into liquid products that are separated from the
unconverted or light material. The liquid product contains a
mixture of only C.sub.8 olefins and C.sub.12 olefins which can be
separated further into two individual streams or be used as a
mixture.
[0182] Table 6 below lists the conditions used in this experiment
and shows that the reaction can proceed under mild conditions. The
presence of pressurized isobutane is designed to enable higher
molecular weight molecules to be removed from the surface of the
catalyst to prevent catalyst deactivation by active site fouling.
It is anticipated that the selectivity of the product towards
C.sub.8s or C.sub.12s can be controlled by control of the space
velocity (WHSV) and the concentration of olefin in the feed. We
expect that higher concentration of olefin and lower space
velocities will favor C.sub.12s because the increased residence
time in the catalyst will allow for more olefins to be in close
contact leading to higher rate of oligomerization reactions to
occur. In contrast, at higher WHSV values and more diluted C4
olefin feed, C8s will tend to be favored due to the lower number of
olefin-olefin encounters.
TABLE-US-00006 TABLE 6 Testing conditions used to generate data.
Parameters Value Feed Isobutane and Isobutene Olefin content 6.7%
Temperature 80.degree. C. Pressure 300 psi WHSV(olefin)
0.4.sup.
[0183] Analysis of the product effluent and the collection times
are listed in Table 7. The high selectivity toward C.sub.8 and
C.sub.12 olefins is theorized to be from a combination of factors
such as large pore size and narrow acidity range of the catalyst
active sites.
TABLE-US-00007 TABLE 7 Composition of the effluent stream
demonstrating the high selectivity for C.sub.8 olefins and C.sub.12
olefins product and low heavy impurity. Sample 1 Sample 2 Sample 3
Time on Stream (h) 143 167 191 Conversion .sup. 89% .sup. 92% .sup.
92% Product Selectivity (wt %) C.sub.8 olefins 41.1% 40.0% 38.9%
C.sub.12 olefins 58.5% 59.7% 60.7% C.sub.16+ olefins 0.4% 0.2%
0.4%
[0184] In this example different MOF's with different pore sizes
were used for light olefin oligomerization. MOF-808 with a pore
size of 14A, PCN-777 with a pore size of 32 .ANG., and NU-1000 with
a pore size of 32 .ANG. were tested.
[0185] FIG. 27 depicts oligomerization completion rates in these
various sulfated MOFs.
[0186] Table 8 below describes the pore variation effect on
oligomerization activity in oxyanion MOFs
TABLE-US-00008 TABLE 8 Molecule (mol %) MOF-808-SO.sub.4
PCN-777-SO.sub.4 C.sub.8 Olefin 94.2 92.3 C.sub.12 Olefin 4.7 7.5
C.sub.12+ Olefin 0.1 0.2
[0187] In closing, it should be noted that the discussion of any
reference is not an admission that it is prior art to the present
invention, especially any reference that may have a publication
date after the priority date of this application. At the same time,
each and every claim below is hereby incorporated into this
detailed description or specification as an additional embodiment
of the present invention.
[0188] Although the systems and processes described herein have
been described in detail, it should be understood that various
changes, substitutions, and alterations can be made without
departing from the spirit and scope of the invention as defined by
the following claims. Those skilled in the art may be able to study
the preferred embodiments and identify other ways to practice the
invention that are not exactly as described herein. It is the
intent of the inventors that variations and equivalents of the
invention are within the scope of the claims while the description,
abstract and drawings are not to be used to limit the scope of the
invention. The invention is specifically intended to be as broad as
the claims below and their equivalents.
* * * * *