U.S. patent application number 16/493275 was filed with the patent office on 2021-01-28 for supported bimetallic core-shell structure catalyst and its preparation method.
This patent application is currently assigned to Beijing University of Chemical Techhnology. The applicant listed for this patent is BEIJING UNIVERSITY OF CHEMICAL TECHNOLOGY. Invention is credited to Junting FENG, Yongjun FENG, Yufei HE, Dianqing LI, Rui MA.
Application Number | 20210023536 16/493275 |
Document ID | / |
Family ID | 1000005169660 |
Filed Date | 2021-01-28 |
United States Patent
Application |
20210023536 |
Kind Code |
A1 |
LI; Dianqing ; et
al. |
January 28, 2021 |
SUPPORTED BIMETALLIC CORE-SHELL STRUCTURE CATALYST AND ITS
PREPARATION METHOD
Abstract
The purpose of the invention is to provide a supported
bimetallic core-shell structure catalyst and its preparation
method. Supporter, metal salt and reducing agent solution are mixed
to synthesize the catalyst M@PdM/ZT by using a one-step synthesis
method, wherein the active metal particle M@PdM as core-shell
structure, M Is the core representing one of the Ag, Pt, Au and Ir.
ZT is the supporter, representing one of hydrotalcite
(Mg.sub.2Al-LDH), alumina (Al.sub.2O.sub.3) and silica (SiO.sub.2).
By changing the temperature and the reaction time to control the
kinetic behavior of the reduction of two kinds of metal ions to
realize the construction of core-shell structure. Active metal
particle composition and shell thickness are regulated by
controlling metal ion concentration. The bimetallic core-shell
catalyst prepared by this method showed excellent selectivity and
stability in acetylene selective hydrogenation and anthraquinone
hydrogenation.
Inventors: |
LI; Dianqing; (Beijing,
CN) ; MA; Rui; (Beijing, CN) ; HE; Yufei;
(Beijing, CN) ; FENG; Yongjun; (Beijing, CN)
; FENG; Junting; (Beijing, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BEIJING UNIVERSITY OF CHEMICAL TECHNOLOGY |
Beijing |
|
CN |
|
|
Assignee: |
Beijing University of Chemical
Techhnology
Beijing
CN
|
Family ID: |
1000005169660 |
Appl. No.: |
16/493275 |
Filed: |
November 2, 2018 |
PCT Filed: |
November 2, 2018 |
PCT NO: |
PCT/CN2018/113555 |
371 Date: |
September 11, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B01J 23/50 20130101;
C07C 5/09 20130101; C07C 2523/50 20130101; B01J 37/343 20130101;
C07C 2521/04 20130101; B01J 37/0236 20130101; C07C 2521/10
20130101; B01J 37/0221 20130101; B01J 23/468 20130101; B01J 21/04
20130101; B01J 21/08 20130101; C07C 2523/52 20130101; C07C 2521/08
20130101; B01J 37/009 20130101; B01J 37/16 20130101; B01J 37/06
20130101; B01J 27/236 20130101; B01J 23/52 20130101 |
International
Class: |
B01J 23/52 20060101
B01J023/52; B01J 23/50 20060101 B01J023/50; B01J 23/46 20060101
B01J023/46; B01J 27/236 20060101 B01J027/236; B01J 21/08 20060101
B01J021/08; B01J 21/04 20060101 B01J021/04; B01J 37/34 20060101
B01J037/34; B01J 37/16 20060101 B01J037/16; B01J 37/02 20060101
B01J037/02; B01J 37/00 20060101 B01J037/00; B01J 37/06 20060101
B01J037/06; C07C 5/09 20060101 C07C005/09 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 23, 2018 |
CN |
201811234759.0 |
Claims
1. A preparation method of supported bimetallic core-shell catalyst
comprising: adding M salt and Pd salt to a reducing solution to
obtain a mixed salt solution after ultrasonic irradiation for 4-5
min; wherein a total concentration of M and Pd ions is 0.01-20
mmol/L, a molar ratio of M:Pd ions is 0.1 to 10; M is one of Ag,
Pt, Au and Ir; M salt is one of AgNO.sub.3, HPtCl.sub.6,
Pt(C.sub.5H.sub.7O.sub.2).sub.2, H.sub.2IrCl.sub.6.6H.sub.2O,
Ir(C.sub.5H.sub.7O.sub.2).sub.3 and HAuCl.sub.4.4H.sub.2O; Pd salt
is one of the PdCl.sub.2, Pd(NO.sub.3).sub.2,
Pd(C.sub.5H.sub.7O.sub.2).sub.2, Pd(CH.sub.3COO).sub.2; the
reducing solution is a mixture of reducing agent and deionized
water, wherein, a mass ratio of the deionized water is 0-20%; the
reducing agent is one of ethylene glycol, isopropanol, N,
n-dimethyl acetamide, N, n-dimethyl formamide and glyceraldehyde;
stirring and heating the mixed salt solution for 10-30 min under
40-50.degree. C., adding a supporter and continuing to stir for
10-20min; raising temperature to 100-160.degree. C. and keeping the
temperature for 0.5-24 h to obtain a black precipitate suspension;
dropping to room temperature to obtain gray or black powders after
centrifuging, washing and drying; wherein the gray or black powders
are catalyst M@PdM/ZT containing metal active ingredient particles
dispersed on the supporter; the metal active ingredient particles
are of a core-shell structure with M being the core and PdM alloy
being the shell; the supporter is one of alumina (Al.sub.2O.sub.3),
silica (SiO2) and hydrotalcite (Mg.sub.2Al-LDH).
2. A supported bimetallic core-shell catalyst M@PdM/ZT comprising
metal active ingredient particles dispersed on a supporter, wherein
the active metal ingredient particles contain M and PdM alloy and
are of a core-shell structure; M is the core with a diameter of
5-15 nm, and selected from the group consisting of Ag, Pt, Au and
Ir; PdM alloy is the shell with a thickness of 1-10 nm; ZT is the
supporter, and selected from the group consisting of hydrotalcite
(Mg.sub.2Al -LDH), alumina (Al.sub.2O.sub.3) and silica
(SiO.sub.2).
Description
TECHNICAL FIELD
[0001] The present disclosure relates to the field of catalyst
preparation, in particular to a supported bimetallic core-shell
structure catalyst and its preparation method.
BACKGROUND ART
[0002] As the basis of energy conversion, heterogeneous catalysis
plays an important role in the national economy, new and efficient
supported catalysts have been an important force to promote the
development of multiphase catalysis. Due to the synergistic effect
between the two metals (including geometric effect and electronic
effect), bimetallic catalysts have adjustable composition and
structure. It is widely used in selective hydrogenation, oxidation,
hydrolysis and reforming reactions.
[0003] Bimetallic catalysts can be divided into alloy structure,
heterogeneous structure and core-shell structure according to the
distribution of the two metals. Due to the difference of core-shell
composition, the composition of bimetallic core-shell structure is
more diverse, and highly adjustable. Compared with alloy structure,
core-shell structure has its unique chemical properties such as
electron transfer between nuclear and shell layers, lattice strain
of surface metal atoms, and full exposure of active metal on the
surface. However, core-shell structure with single metal shell M@N
(M and N represent one metal each) has poor stability, and it is
difficult to maintain structural stability under harsh reaction
conditions. Therefore, design and synthesis a bimetallic core-shell
structure with bimetallic alloy shell and single metal core is
necessary, this kind of structure have the advantages of core-shell
structure as well as the stability of alloy which is important for
improving the performance of bimetallic catalytic materials.
[0004] However, the controllable preparation of this kind of
materials is still a challenge. In recent years, it has been
reported that the supported core-shell structure is prepared by
crystal seed epitaxial. Min Meng, etc, Nano Letters, 2016, 16,
3036, prepared a Pd@AuCu core-shell structure through the
regulation of ion reduction kinetics of Au and Cu ions, wherein, Pd
cube as crystal seed, hexadecyl trimethylammonium chloride as
ending agent, and glucose as reducing agent. Vismadeb Mazumder etc,
JACS, 2010, 132, 7848, obtained Pd@PtFe nanoparticles by growing
FePt alloy on the surface of Pd nanoparticles with the presence of
surfactant by two-step method. However, epitaxial growth method has
the disadvantages such as: complicated preparation methods and the
active sites is often covered by surfactant residues. Therefore,
designing a simple and feasible one-step method to prepare M@NM
bimetallic core shell structure without surfactant and protectant
is still one of the difficulties in the field of nanomaterials.
[0005] In conclusion, supported core-shell structure has a high
research value in the field of multiphase catalysis due to its
unique structural characteristics, and radiates to the fields of
electrocatalysis, photocatalysis and optical devices. However, the
preparation methods reported in existing literatures have some
shortcomings, such as complicated reaction conditions, difficult
operation, high cost and so on. Therefore, the controllable
preparation of supported core-shell bimetallic catalysts and the
application of such catalysts in heterogeneous catalytic reactions
still need to be further studied.
SUMMARY
[0006] The purpose of the invention is to provide a supported
bimetallic core-shell structure catalyst and its preparation
method. It has been used in petroleum and fine chemical industry
and has good application effect for selective hydrogenation of
acetylene and anthraquinone. Supported bimetallic core-shell
catalyst provided by the invention is expressed as M@PdM/ZT, active
metal particles M@PdM are core-shell structures, M Is the core with
a diameter of 5-15 nm, representing one of the Ag, Pt, Au and Ir;
PdM alloy is the shell structure with a thickness of 1-10 nm; ZT is
the supporter, representing one of hydrotalcite (Mg2A1-LDH),
alumina (Al.sub.2O.sub.3) and silica (SiO.sub.2);
[0007] The preparation method of supported bimetallic core-shell
catalyst provided by the invention has the following steps:
[0008] A. M salt and Pd salt are added to the reducing solution to
obtain mixed salt solution after ultrasonic irradiation for 4-5
min; wherein the total concentration of M and Pd ions is
.sup.0.01-20 mmol/L, the molar ratio of the M:Pd ions is 0.1 to
10;
[0009] The M is one of Ag, Pt, Au and Ir; M salt is one of
AgNO.sub.3, HPtCl.sub.6, Pt(C.sub.5H.sub.7O.sub.2).sub.2,
H.sub.2IrCl.sub.6.6H.sub.2O, Ir(C.sub.5H.sub.7O.sub.2).sub.3 and
HAuCl.sub.4.4H.sub.2O; Pd salt is one of the PdCl.sub.2,
Pd(NO.sub.3).sub.2, Pd(C.sub.5H.sub.7O.sub.2).sub.2,
Pd(CH.sub.3COO).sub.2; the reducing solution is a mixture of
reducing agent and deionized water, wherein, the mass ratio of
deionized water is 0-20%; the reducing agent is one of ethylene
glycol, isopropanol, N, n-dimethyl acetamide, N, n-dimethyl
formamide and glyceraldehyde.
[0010] B. Mixed salt solution obtained in A is stirred and heated
for 10-30 min under 40-50.degree. C., add the supporter and
continue to stir for 10-20 min, heat up the temperature to
100-160.degree. C. and keep it for 0.5-24 h to obtain black
precipitate suspension, drop to room temperature to obtain gray or
black powder after centrifuging, washing and drying; It is proved
as catalyst M@PdM/ZT by characterization; its metal active
ingredient particles are core-shell structure, wherein M is the
core and PdM alloy is the shell. The supporter is one of alumina
(Al.sub.2O.sub.3), silica (SiO.sub.2) and hydrotalcite (Mg.sub.2Al
-LDH);
[0011] FIG. 1 is the electron microscope image of catalyst
Ag@PdAg/Mg.sub.2Al -LDH prepared by embodiment 1. It can be seen
that the metal active ingredient particles in the supported
catalyst are evenly dispersed on hydrotalcite supporter, and
crystal shape and size of metal particles are intact, with an
average particle size of 15.6 nm.
[0012] FIG. 2 shows the EDX linear sweep results of metal Pd and Ag
in metal particles of catalyst Ag@PdAg/Mg.sub.2Al -LDH prepared by
embodiment 1. By comparing the distribution of Pd and Ag, it can be
seen that Ag is distributed throughout the metal particles while Pd
is concentrated on the surface of the metal particles. Therefore,
it can be concluded that the metal active ingredient particles of
this catalyst is core-shell structures that PdAg coated on the
surface of Ag. In addition, it can be seen from the linear sweep
results of element Pd in FIG. 2 that the shell thickness of PdAg
alloy is 4nm and the core diameter is 8 nm.
[0013] FIG. 3 shows the X-ray photoelectron spectroscopy of Pd in
catalyst Ag@PdAg/Mg.sub.2Al-LDH prepared by embodiment 1. Compared
with single metal, Pd electron binding energy shift indicates that
PdAg alloy is formed on the surface of prepared catalyst metal
particles.
[0014] FIG. 4 shows the changing curve of ethylene selectivity with
temperature in selective hydrogenation of acetylene when using the
catalyst Ag@PdAg/Mg2Al-LDH prepared by embodiment 1. The
selectivity of ethylene is higher than 95% in the range of
30-100.degree. C. temperature.
[0015] FIG. 5 shows the changing curve of acetylene conversion and
ethylene selectivity with time in selective hydrogenation of
acetylene when using the catalyst Ag@PdAg/Mg.sub.2Al-LDH prepared
by embodiment 1. As can be seen from the figure, the catalyst did
not deactivate after the reaction for 50 h, and the acetylene
conversion rate remained above 96%. The selectivity of ethylene
shows a similar trend and remained above 93% after long reaction
time.
[0016] FIG. 6 is the electron microscope image of catalyst
Ag@PdAg/Mg2Al-LDH prepared by embodiment 1 after 48h selective
hydrogenation of acetylene. It can be seen from the figure that
after a long time of reaction, there is no agglomeration of metal
particles in the catalyst, and the metal active ingredient
particles are evenly dispersed on the surface of hydrotalcite
supporter.
[0017] FIG. 7 is a scanning transmission electron microscope (STEM)
photo of metal particles of catalyst Au@PdAu/Si02 prepared by
embodiment 2. As can be seen from the photo, metal particle size of
Au@PdAu is about 15 nm. The brightness of metal particles bulk
phase and surface is different (the brightness of STEM photos is
determined by the atomic number of metal atoms, the larger the
atomic number, the brighter it is), the surface brightness of metal
particles is lower than the central part, indicating that metal Pd
is concentrated on the surface of metal particles. In addition, by
measuring the lattice fringe, it can be known that the bulk phase
of the metal particle is Au, that is, the metal particle is a
core-shell structure with Au as the core and PdAu as the shell, the
shell thickness is about 2 nm.
[0018] FIG. 8 shows the changing curves of hydrogenation efficiency
of the catalyst prepared by embodiment 1 and embodiment 2 in the
hydrogenation of anthraquinone. The initial hydrogenation
efficiency of both catalysts can reach 13.9 g/L. Moreover, the
hydrogenation efficiency of the catalyst remained above 14.2 g/L
after the reaction for 300 min, indicating that the bimetallic
core-shell catalyst had excellent stability in reaction.
[0019] FIG. 9 shows the changing curves of effective anthraquinone
selectivity with time of the catalyst prepared by embodiment 1 and
the catalyst prepared by embodiment 2 in the hydrogenation of
anthraquinone. As can be seen from the figure, the effective
anthraquinone selectivity of the core-shell structure catalyst
remained above 95% after 5 h reaction.
[0020] The beneficial effect of the invention is: the supporter,
metal salt and reducing agent solution are mixed to synthesize the
catalyst M@PdM/ZT by using a one-step synthesis method, wherein
active metal particle M@PdM as core-shell structure, and the shell
is PdM alloy. By changing the temperature and the reaction time to
control the kinetic behavior of the reduction of two kinds of metal
ions to realize the construction of core-shell structure; Active
metal particle composition and shell thickness are regulated by
controlling metal ion concentration. This method is simple and
universal, which can not only fully expose the reactive sites of
active metals, but also give full play to the synergistic effect
between the two metals. The bimetallic core-shell catalyst prepared
by this method showed excellent selectivity and stability in
acetylene selective hydrogenation and anthraquinone
hydrogenation.
APPENDED DRAWINGS
[0021] FIG. 1 is the electron microscope image of catalyst
Ag@PdAg/Mg2A1-LDH prepared by embodiment 1.
[0022] FIG. 2 is the EDX linear sweep results of metal Pd and Ag in
metal particles of catalyst Ag@PdAg/Mg.sub.2Al-LDH prepared by
embodiment 1.
[0023] FIG. 3 is the X-ray photoelectron spectroscopy of Pd in
catalyst Ag@PdAg/Mg.sub.2Al-LDH prepared by embodiment 1.
[0024] FIG. 4 is the changing curve of ethylene selectivity with
temperature in selective hydrogenation of acetylene when using the
catalyst Ag@PdAg/Mg.sub.2Al-LDH prepared by embodiment 1.
[0025] FIG. 5 is the changing curve of acetylene conversion and
ethylene selectivity with time in selective hydrogenation of
acetylene when using the catalyst Ag@PdAg/Mg.sub.2Al-LDH prepared
by embodiment 1.
[0026] FIG. 6 is the electron microscope image of catalyst
Ag@PdAg/Mg2A1-LDH prepared by embodiment 1 after 48 h selective
hydrogenation of acetylene.
[0027] FIG. 7 is the scanning transmission electron microscope
(STEM) photo of metal particles of catalyst Au@PdAu/SiO.sub.2
prepared by embodiment 2.
[0028] FIG. 8 is the changing curves of hydrogenation efficiency of
the catalyst prepared by embodiment 1 and embodiment 2 in the
hydrogenation of anthraquinone.
[0029] FIG. 9 is the changing curves of effective anthraquinone
selectivity with time of the catalyst prepared by embodiment 1 and
the embodiment 2 in the hydrogenation of anthraquinone.
PREFERRED EMBODIMENTS
[0030] The present invention is further described in detail in
combination with the appended drawings.
Embodiment 1
[0031] Add 0.008mmol Pd(C.sub.5H.sub.7O.sub.2).sub.2, 0.08mmol
AgNO3 into 100 ml N,N-Dimethylformamide to obtain mixed salt
solution after 5 min ultrasonic irradiation. Pure the mixed
solution in a flask and put it on an oil bath for stirring and
heating for 10 min under 50.degree. C., add 1 g Mg.sub.2Al-LDH and
continue to stir for 10 min, heat up the temperature to 130.degree.
C. and keep it for 2 h to obtain black precipitate suspension, drop
to room temperature to obtain black powder after centrifuging,
washing and drying. It is proved as catalyst Ag@PdAg/Mg2Al -LDH by
characterization; its metal active ingredient particles are
core-shell structure, wherein PdAg alloy is the shell.
Embodiment 2
[0032] Add 0.01 mmol Pd(CH.sub.3COO).sub.2, 0.04mmoln
HAuCl.sub..4H.sub.2O into 100 ml Eethylene glycol aqueous solution
(the mass ratio of deionized water is 20%) to obtain mixed salt
solution after 5 min ultrasonic irradiation with stirring. Pure the
mixed solution in a flask and put it on an oil bath for stirring
and heating for 0.5 h under 50.degree. C., add 0.5 g amorphous
silica powder and continue to stir for 10 min, heat up the
temperature to 110.degree. C. and keep it for 12 h to obtain black
precipitate suspension, drop to room temperature to obtain black
powder after centrifuging, washing and drying. It is proved as
catalyst Au@PdAu/SiO.sub.2 by characterization; its metal active
ingredient particles are core-shell structure, wherein PdAu alloy
is the shell.
Embodiment 3
[0033] Add 0.002 mmol Pd(NO.sub.3).sub.2, 0.06 mmolAgNO.sub.3 into
100 ml N,N-dimethylformamide aqueous solution (the mass ratio of
deionized water is 10%) to obtain mixed salt solution after 5 min
ultrasonic irradiation with stirring. Pure the mixed solution in a
flask and put it on an oil bath for stirring and heating for lh
under 40.degree. C., add 1 g Al.sub.2O.sub.3 powder and continue to
stir for 10 min, heat up the temperature to 130.degree. C. and keep
it for 2 h to obtain black precipitate suspension, drop to room
temperature to obtain gray powder after centrifuging, washing and
drying. It is proved as catalyst Ag@PdAg/Al.sub.2O.sub.3 by
characterization; its metal active ingredient particles are
core-shell structure, wherein PdAg alloy is the shell.
Embodiment 4
[0034] Add 0.005 mmol Ir(C.sub.5H.sub.7O.sub.2).sub.3, 0.001
mmolPdCl.sub.2 into 100 ml isopropanol aqueous solution (the mass
ratio of deionized water is 10%) to obtain mixed salt solution
after 5 min ultrasonic irradiation with stirring. Pure the mixed
solution in a flask and put it on an oil bath for stirring and
heating for 0.5 h under 40.degree. C., add 2 g Mg.sub.2Al-LDH
powder and continue to stir for 10 min, heat up the temperature to
100.degree. C. and keep it for lh to obtain black precipitate
suspension, drop to room temperature to obtain gray powder after
centrifuging, washing and drying. It is proved as catalyst
Ir@PdIr/Mg.sub.2Al-LDH by characterization; its metal active
ingredient particles are core-shell structure, wherein Pdlr alloy
is the shell.
Embodiment 5
[0035] Add 0.01 mmol Pd(CH.sub.3COO).sub.2, 0.004
mmolHPtCl.sub.6into 100 ml N,N-dimethylacetamide solution to obtain
mixed salt solution after 5 min ultrasonic irradiation with
stirring. Pure the mixed solution in a flask and put it on an oil
bath for stirring and heating for 0.5 h under 45.degree. C., add 2
g Al.sub.2O.sub.3 powder and continue to stir for 10 min, heat up
the temperature to 160.degree. C. and keep it for 12 h to obtain
black precipitate suspension, drop to room temperature to obtain
black powder after centrifuging, washing and drying. It is proved
as Pt@PdPt/Al.sub.2O.sub.3 catalyst by characterization; its metal
active ingredient particles are core-shell structure, wherein PdPt
alloy is the shell.
APPLICATION EXAMPLE 1
[0036] Evaluate the performance of acetylene selective
hydrogenation of the catalyst in embodiment 1-5 and the comparison
sample.
[0037] The evaluation device is WFS-3015 microreactor of Tianjin
xianquan instrument co. LTD. The operation steps are as
follows:
[0038] 0.1 g catalyst samples are weighed, mixed with 1.9 g quartz
sand (40-80 mesh) and placed in quartz reaction tubes. Before the
reaction, raise the temperature of reaction bed to 150.degree. C.
and process the catalyst pretreatment with nitrogen for 1 hour. The
nitrogen flow rate is 50 ml/l min. After the pretreatment and the
reaction bed temperature drops to room temperature, feed nitrogen,
ethylene acetylene mixture and hydrogen with the flow rate of 111,
55.5 and 1.0 ml/min respectively. The percentage of acetylene in
ethylene-acetylene mixture is 0.947%, and the ratio of hydrogen
acetylene is about 2. Control the reaction temperature is
100.degree. C., the reaction airspeed is 10050 h.sup.-1, and the
relative pressure of the reaction system is 0.4 MPa. The
concentrations of reactants and products are analyzed by online gas
chromatography, capillary column is 0.53*50 mm and the detector
adopts hydrogen flame detector. Normalization method is adopted for
data processing. The results of acetylene conversion and ethylene
selectivity of catalyst under 100.degree. C. are shown in table
1:
TABLE-US-00001 TABLE 1 Catalyst Embodiment Embodiment Embodiment
Embodiment Embodiment sample 1 2 3 4 5 comparison Acetylene 100 94
87 100 100 86 conversion (%) Ethylene 94 91 100 74 91 72
selectivity (%)
[0039] Wherein, the comparison is catalyst PdPtAg/Mg.sub.2Al-LDH
which is disclosed in CN103977794B, this catalyst is specially
designed for selective hydrogenation of acetylene.
APPLICATION EXAMPLE 2
[0040] Evaluate the performance anthraquinone hydrogenation of the
catalyst in embodiment 1-5 and the comparison sample.
[0041] The evaluation device is PTFE internal tank reactor with
magnetic stirring and heating device, 25 g catalyst and 60ml
anthraquinone working solution (100 g/L anthraquinone working
solution is composed of 100 g 2-ethyl anthraquinone, 1,3,
5-tritoluene and 400 mL trioctyl phosphate) are added to the
reactor and sealed, injecting hydrogen into the reactor through a
cylinder to replace the air, repeat 5 times. Heat up the reactor to
50.degree. C., fill with hydrogen, make the pressure reach 0.3 MPa
and adjust the stirring speed to 1200 rpm/min, then start to
timing. After the 1.5 h reaction, the reaction samples are
collected from the reaction gas outlet valve for activity and
selectivity evaluation and the yield of H.sub.2O.sub.2 is
calculated. The yield of H.sub.2O.sub.2 and spatio-temporal yield
of catalyst are shown in table 2.
TABLE-US-00002 TABLE 2 Catalyst Embodiment Embodiment Embodiment
Embodiment Embodiment sample 1 2 3 4 5 comparison yield of 14.30
13.58 13.09 14.10 12.69 11.00 H.sub.2O.sub.2(g/mL) Spatio-temporal
2884 2715 2618 2618 2538 2200 yield (gH.sub.2O.sub.2/ (gPd h))
[0042] Wherein, the comparison is catalyst Pd/Al.sub.2O.sub.3 which
is disclosed in CN103172097A, this catalyst is specially designed
for anthraquinone hydrogenation.
* * * * *