Platinum/carbon catalyst is one of the most important catalysts in hydrogenation of ortho-nitrochlorobenzene to 2,2′-dichlorohydrazobenzene. The preparation process and the supports of catalysts are studied in this p...Platinum/carbon catalyst is one of the most important catalysts in hydrogenation of ortho-nitrochlorobenzene to 2,2′-dichlorohydrazobenzene. The preparation process and the supports of catalysts are studied in this paper. Raw materials and preparation procedure of the activated carbon have great influences on the compositions and surface structure of platinum/carbon catalysts. Platinum catalysts supported on activated carbon with high purity, high surface area, large pore volume and appropriate pore structure usually exhibit higher activities for hydrogenation of ortho-nitrochlorobenzene to 2,2′-dichlorohydrazobenzene. The catalyst prepared from H2PtCl6 with pH=3 shows greater catalytic performance than those prepared under other conditions.展开更多
Exploring advanced platinum (Pt)-based electrocatalysts is vital for the widespread implementation of proton exchange membrane fuel cells (PEMFCs). Morphology control represents an effective strategy to optimize the b...Exploring advanced platinum (Pt)-based electrocatalysts is vital for the widespread implementation of proton exchange membrane fuel cells (PEMFCs). Morphology control represents an effective strategy to optimize the behavior of Pt catalysts. In this work, an attempt is made to comprehensively review the effect of morphology control on the catalytic behavior of catalysts in the oxygen reduction reaction (ORR). First, the fundamental physicochemical changes behind morphology control, including exposing more active sites, generating appropriate lattice strains, and forming different crystalline surfaces, are highlighted. Then, recently developed strategies for tuning the morphologies of electrocatalysts, including core-shell structures, hollow structures, nanocages, nanowires, and nanosheets, are comprehensively summarized. Finally, an outlook on the future development of morphology control of Pt catalysts is presented, including rational design strategies, advanced in situ characterization techniques, novel artificial intelligence, and mechanical learning. This work is intended to provide valuable insights into designing the morphology and technological innovation of efficient redox electrocatalysts in fuel cells.展开更多
Hydroisomerization catalysts Pt/ZSM-22, Pt/ZSM-23, and Pt/ZSM-22/ZSM-23 were prepared by supporting Pt on ZSM-22, ZSM-23, and intergrowth zeolite ZSM-22/ZSM-23, respectively. The typical physicochemical properties of ...Hydroisomerization catalysts Pt/ZSM-22, Pt/ZSM-23, and Pt/ZSM-22/ZSM-23 were prepared by supporting Pt on ZSM-22, ZSM-23, and intergrowth zeolite ZSM-22/ZSM-23, respectively. The typical physicochemical properties of these catalysts were characterized by X-Ray Diffraction （XRD）, N2 absorption-desorption, Pyridine-Fourier Transform Infrared （Py-FTIR）, Transmission Electron Microscopy （TEM）, X-Ray Fluorescence （XRF）, Scanning Electron Microscopy （SEM） and NH3- Temperature Programmed Desorption （NH3-TPD）, and the performance of these catalysts in n-dodecane hydroisomerization was evaluated in a continuous down-flow fixed bed with a stainless steel tubular reactor. The characterization results indicated that the intergrowth zeolite ZSM-22/ZSM-23 possessed the dual structure of ZSM-22 and ZSM-23, and the catalyst Pt/ZSM-22/ZSM-23 had similar pores and weak acidity to Pt/ZSM-22 and Pt/ZSM-23 catalysts. Moreover, Pt/ZSM-22/ZSM-23 catalyst showed a high selectivity in hydroisomerization of long chain n-alkanes to mono-branched isomers. The evaluation results for n-dodecane hydroisomerization indicated that the activity of Pt/ZSM-22/ZSM-23 was the lowest, while the hydroisomerization selectivity was the highest among the three catalysts. The maximum yield of i-dodecane product was 68.3% over Pt/ZSM-22/ZSM-23 at 320 ℃.展开更多
Platinum catalyst for CO oxidation has been studied for decades,due to its high activity and good stability.In this work,we prepared three different lantha num oxide or hydroxide supports(LaO_(x)(OH)_(y)),and deposite...Platinum catalyst for CO oxidation has been studied for decades,due to its high activity and good stability.In this work,we prepared three different lantha num oxide or hydroxide supports(LaO_(x)(OH)_(y)),and deposited platinum(Pt) with 0.5 at% via an impregnation approach to synthesize Pt/LaO_(x)(OH)_(y) catalysts.However,we find that these catalysts perform a poor stability for the CO oxidation reaction.The fresh and used samples were comprehensively characterized by multiple techniques including power X-ray diffraction(XRD),X-ray absorption fine structure(XAFS),transmission electron microscopy(TEM),temperature-programmed reduction by carbon monoxide(CO-TPR) and thermogravimetric analysis(TGA),to demonstrate that the oxidized platinum atoms or clusters,without any component of Pt-Pt metallic bond,are highly dispersed on the surface of LaO_(x)(OH)_(y).Furthermore,the as-formed lanthanum carbonate(La_(2)O_(2)CO_(3)) during the exposure to ambient circumstances or in the reaction atmosphere of CO+O_(2),severely impair the reactivity of Pt/LaO_(x)(OH)_(y).On the basis of the obtained experimental results,we have drawn a conclusion that the oxidized P_(t)O_(x) atoms or PtxOy clusters are the active species for CO oxidation,while the formation of lanthanum carbonate is the origin of deactivation on reactivity.展开更多
Ceria supported platinum catalyst has now been widely studied due to its excellent activity for CO oxidatio n.However,the electron state of active metal center is still an open question.In this work,a ce ria nanorod s...Ceria supported platinum catalyst has now been widely studied due to its excellent activity for CO oxidatio n.However,the electron state of active metal center is still an open question.In this work,a ce ria nanorod support was prepared and platinum(Pt)with 0.9 at%was deposited using an impregnation method to obtain Pt/CeO_(2)catalyst.With the help of"light-off"experiment and temperatureprogrammed reduction under CO(CO-TPR)test,the conclusion is proposed that the process of hydrogen reduction can enhance the activity of CO oxidation reaction for the generation of optimal active Pt site.An innovative near-situ X-ray absorption fine structure(XAFS)technique was used to investigate the chemical state of central Pt atom during the reaction process,clearly demonstrating that the high oxidized state of Pt does harm to the activity for CO oxidation while the relatively reductive Pt exhibits high activity,and the different oxidized state and chemical environment of Pt during every process has been identified.Furthermore,the activity of our Pt/CeO_(2)catalyst is superior to that of most of the previous reports about CO catalytic oxidation by Pt based catalyst.Moreover,the optimal active species(Pt-O_(4))have been identified after hydrogen reduction,which could be a possible key strategy to control the oxidation of Pt.展开更多
An extensive study has been conducted on the proton exchange membrane fuel cells （PEMFCs） with reducing Pt loading. This is commonly achieved by developing methods to increase the utilization of the platinum in the ...An extensive study has been conducted on the proton exchange membrane fuel cells （PEMFCs） with reducing Pt loading. This is commonly achieved by developing methods to increase the utilization of the platinum in the catalyst layer of the electrodes. In this paper, a novel process of the catalyst layers was introduced and investigated. A mixture of carbon powder and Nafion solution was sprayed on the glassy carbon electrode （GCE） to form a thin carbon layer. Then Pt particles were deposited on the surface by reducing hexachloroplatinic （IV） acid hexahydrate with methanoic acid. SEM images showed a continuous Pt gradient profile among the thickness direction of the catalytic layer by the novel method. The Pt nanowires grown are in the size of 3 nm （diameter） x l0 nm （length） by high solution TEM image. The novel catalyst layer was characterized by cyclic voltammetry （CV） and scanning electron microscope （SEM） as compared with commercial Pt/C black and Pt catalyst layer obtained from sputtering. The results showed that the platinum nanoparticles deposited on the carbon powder were highly utilized as they directly faced the gas diffusion layer and offered easy access to reactants （oxygen or hydrogen）.展开更多
1, 1'--Bis(benzylseleno)ferrocene and its platinum complex were synthesized. It was found that the platinum complex was efficient catalyst for the hydrosilylation of olefins with triethoxysilane.
Fabrication of novel electrode architectures with nanostructured ultrathin catalyst layers is an effective strategy to improve catalyst utilization and enhance mass transport for polymer electrolyte membrane fuel cell...Fabrication of novel electrode architectures with nanostructured ultrathin catalyst layers is an effective strategy to improve catalyst utilization and enhance mass transport for polymer electrolyte membrane fuel cells (PEMFCs).Herein,we report the design and construction of a nanostructured ultrathin catalyst layer with ordered Pt nanotube arrays,which were obtained by a hard-template strategy based on ZnO,via hydrothermal synthesis and magnetron sputtering for PEMFC application.Because of the crystallographically preferential growth of Pt (111) facets,which was attributed to the structural effects of ZnO nanoarrays on the Pt nanotubes,the catalyst layers exhibit obviously higher electrochemical activity with remarkable enhancement of specific activity and mass transport compared with the state-of-the-art randomly distributed Pt/C catalyst layer.The PEMFC fabricated with the as-prepared catalyst layer composed of optimized Pt nanotubes with an average diameter of 90(±10) nm shows excellent performance with a peak power density of 6.0W/mgPt at 1 A/cm^2,which is 11.6%greater than that of the conventional Pt/C electrode.展开更多
A modified method of preparing crown functionalized linear polysiloxane has been described.4'-allylbenzo-15-crown-5 was subjected to hydrosilylation with methyldichlorosilane,followed bypolycondensation with silan...A modified method of preparing crown functionalized linear polysiloxane has been described.4'-allylbenzo-15-crown-5 was subjected to hydrosilylation with methyldichlorosilane,followed bypolycondensation with silanol-terminated polydimethylsiloxane to give the title crownfunctionalized linear polysiloxane. It was found that the polysiloxane could be coordinated withplatinum salt to form platinum complex, which could catalyze the hydrosilylation of olefins withtriethoxysilane efficiently.展开更多
Silica-bound 15-Crown-5, 18-Crown-6 with a spacer of propyloxymethyl and their platinum complexes have been synthesized. It was found that they were efficient catalysts for the hydrosilylation of olefms with triethoxy...Silica-bound 15-Crown-5, 18-Crown-6 with a spacer of propyloxymethyl and their platinum complexes have been synthesized. It was found that they were efficient catalysts for the hydrosilylation of olefms with triethoxysilane in the temperature range of 60 to 130 ℃.展开更多
The addition of platinum over the B2O3/TiO2-ZrO2 remarkably enhanced its catalytic stability in the vapor phase Beckmann rearrangement of cyclohexanone oxime under the carder gas of H2. The content of coke deposited ...The addition of platinum over the B2O3/TiO2-ZrO2 remarkably enhanced its catalytic stability in the vapor phase Beckmann rearrangement of cyclohexanone oxime under the carder gas of H2. The content of coke deposited on catalyst surface was decreased from 1.92% over the B2O3/TiO2-ZrO2 to 1.14% over the platinum promoted B2O3/TiO2-ZrO2 after reaction of six hours. This result indicates that the platinum added on the B2O3/TiO2-ZrO2 catalyst plays an important role in reducing the coke formation on the catalyst surface.展开更多
Three-dimensionally ordered macro-/mesoporous alumina（3DOM Al2O3）-supported cobalt oxide and platinum nanocatalysts（xPt/yCo3O4/3DOM Al2O3,Pt mass fraction（x%）= 0-1.4%,Co3O4 mass fraction（y%） = 0-9.2%） were pre...Three-dimensionally ordered macro-/mesoporous alumina（3DOM Al2O3）-supported cobalt oxide and platinum nanocatalysts（xPt/yCo3O4/3DOM Al2O3,Pt mass fraction（x%）= 0-1.4%,Co3O4 mass fraction（y%） = 0-9.2%） were prepared using poly（methyl methacrylate） templating,incipient wetness impregnation and polyvinyl alcohol-protected reduction.The resulting xPt/yCo3O4/3DOM Al2O3 samples displayed a high-quality 3DOM architecture with macropores（180-200 nm in diameter） and mesopores（4-6 nm in diameter） together with surface areas in the range of 94 to 102m^2/g.Using these techniques,Co3O4 nanoparticles（NPs,18.3 nm） were loaded on the 3DOM Al2O3 surface,after which Pt NPs（2.3-2.5 nm） were uniformly dispersed on theyCo3O4/3DOM Al2O3.The1.3Pt/8.9Co3O4/3DOM Al2O3 exhibited the best performance for toluene oxidation,with a T（90%） value（the temperature required to achieve 90%toluene conversion） of 160 ℃ at a space velocity of20000 mL g^（-1） h^（-1）.It is concluded that the excellent catalytic performance of the 1.3Pt/8.9Co3O4/3DOM Al2O3 is owing to well-dispersed Pt NPs,the high concentration of adsorbed oxygen species,good low-temperature reducibility,and strong interaction between the Pt and Co3O4 NPs,as well as the unique bimodal porous structure of the support.展开更多
The Pt decorated Ni/C nanocatalysts were prepared for hydrogen oxidation reaction（HOR） in fuel cell.By regulating the contents of Pt and Ni in the catalyst,both the composition and the structure affected the electro...The Pt decorated Ni/C nanocatalysts were prepared for hydrogen oxidation reaction（HOR） in fuel cell.By regulating the contents of Pt and Ni in the catalyst,both the composition and the structure affected the electrochemical catalytic characteristics of the Pt-Ni/C catalysts.When the Pt mass content was 3.1% percent and that of Ni was 13.9% percent,the Pt-Ni/C-3 catalyst exhibited a larger electrochemically active surface area and a higher exchange current density toward HOR than those of pure supported platinum sample.Our study demonstrates a feasible approach for designing the more efficient catalysts with lower content of noble metal for HOR in fuel cell.展开更多
文摘Platinum/carbon catalyst is one of the most important catalysts in hydrogenation of ortho-nitrochlorobenzene to 2,2′-dichlorohydrazobenzene. The preparation process and the supports of catalysts are studied in this paper. Raw materials and preparation procedure of the activated carbon have great influences on the compositions and surface structure of platinum/carbon catalysts. Platinum catalysts supported on activated carbon with high purity, high surface area, large pore volume and appropriate pore structure usually exhibit higher activities for hydrogenation of ortho-nitrochlorobenzene to 2,2′-dichlorohydrazobenzene. The catalyst prepared from H2PtCl6 with pH=3 shows greater catalytic performance than those prepared under other conditions.
基金the Natural Science Foundation of Shaanxi Province,China(No.2023-JC-YB-122)the High-level Innovation and Entrepreneurship Talent Project from Qinchuangyuan of Shaanxi Province,China(No.QCYRCXM-2022-226)+2 种基金the Fundamental Research Funds for the Central Universities,China(No.D5000210987)the Joint Fund Project-Enterprise-Shaanxi Coal Joint Fund Project,China(No.2021JLM-38)the National Natural Science Foundation of China(Grant No.22379123,No.22250710676),the Fujian Province Minjiang Scholar Program,China.
文摘Exploring advanced platinum (Pt)-based electrocatalysts is vital for the widespread implementation of proton exchange membrane fuel cells (PEMFCs). Morphology control represents an effective strategy to optimize the behavior of Pt catalysts. In this work, an attempt is made to comprehensively review the effect of morphology control on the catalytic behavior of catalysts in the oxygen reduction reaction (ORR). First, the fundamental physicochemical changes behind morphology control, including exposing more active sites, generating appropriate lattice strains, and forming different crystalline surfaces, are highlighted. Then, recently developed strategies for tuning the morphologies of electrocatalysts, including core-shell structures, hollow structures, nanocages, nanowires, and nanosheets, are comprehensively summarized. Finally, an outlook on the future development of morphology control of Pt catalysts is presented, including rational design strategies, advanced in situ characterization techniques, novel artificial intelligence, and mechanical learning. This work is intended to provide valuable insights into designing the morphology and technological innovation of efficient redox electrocatalysts in fuel cells.
基金the financial supports form Petrochina(050508-04-02)the National Natural Science Foundation of China(No.21073235,and 20833011)
文摘Hydroisomerization catalysts Pt/ZSM-22, Pt/ZSM-23, and Pt/ZSM-22/ZSM-23 were prepared by supporting Pt on ZSM-22, ZSM-23, and intergrowth zeolite ZSM-22/ZSM-23, respectively. The typical physicochemical properties of these catalysts were characterized by X-Ray Diffraction （XRD）, N2 absorption-desorption, Pyridine-Fourier Transform Infrared （Py-FTIR）, Transmission Electron Microscopy （TEM）, X-Ray Fluorescence （XRF）, Scanning Electron Microscopy （SEM） and NH3- Temperature Programmed Desorption （NH3-TPD）, and the performance of these catalysts in n-dodecane hydroisomerization was evaluated in a continuous down-flow fixed bed with a stainless steel tubular reactor. The characterization results indicated that the intergrowth zeolite ZSM-22/ZSM-23 possessed the dual structure of ZSM-22 and ZSM-23, and the catalyst Pt/ZSM-22/ZSM-23 had similar pores and weak acidity to Pt/ZSM-22 and Pt/ZSM-23 catalysts. Moreover, Pt/ZSM-22/ZSM-23 catalyst showed a high selectivity in hydroisomerization of long chain n-alkanes to mono-branched isomers. The evaluation results for n-dodecane hydroisomerization indicated that the activity of Pt/ZSM-22/ZSM-23 was the lowest, while the hydroisomerization selectivity was the highest among the three catalysts. The maximum yield of i-dodecane product was 68.3% over Pt/ZSM-22/ZSM-23 at 320 ℃.
基金Project supported by the National Natural Science Foundation of China(21773288)National Key Basic Research Program of China(2017YFA0403402)。
文摘Platinum catalyst for CO oxidation has been studied for decades,due to its high activity and good stability.In this work,we prepared three different lantha num oxide or hydroxide supports(LaO_(x)(OH)_(y)),and deposited platinum(Pt) with 0.5 at% via an impregnation approach to synthesize Pt/LaO_(x)(OH)_(y) catalysts.However,we find that these catalysts perform a poor stability for the CO oxidation reaction.The fresh and used samples were comprehensively characterized by multiple techniques including power X-ray diffraction(XRD),X-ray absorption fine structure(XAFS),transmission electron microscopy(TEM),temperature-programmed reduction by carbon monoxide(CO-TPR) and thermogravimetric analysis(TGA),to demonstrate that the oxidized platinum atoms or clusters,without any component of Pt-Pt metallic bond,are highly dispersed on the surface of LaO_(x)(OH)_(y).Furthermore,the as-formed lanthanum carbonate(La_(2)O_(2)CO_(3)) during the exposure to ambient circumstances or in the reaction atmosphere of CO+O_(2),severely impair the reactivity of Pt/LaO_(x)(OH)_(y).On the basis of the obtained experimental results,we have drawn a conclusion that the oxidized P_(t)O_(x) atoms or PtxOy clusters are the active species for CO oxidation,while the formation of lanthanum carbonate is the origin of deactivation on reactivity.
基金Project supported by Shanghai Large Scientific Facilities CenterNational Key Basic Research Program of China(2017YFA0403402)+1 种基金the National Natural Science Foundation of China(U1932119)This work was also supported by Shanghai Large Scientific Facilities Center.
文摘Ceria supported platinum catalyst has now been widely studied due to its excellent activity for CO oxidatio n.However,the electron state of active metal center is still an open question.In this work,a ce ria nanorod support was prepared and platinum(Pt)with 0.9 at%was deposited using an impregnation method to obtain Pt/CeO_(2)catalyst.With the help of"light-off"experiment and temperatureprogrammed reduction under CO(CO-TPR)test,the conclusion is proposed that the process of hydrogen reduction can enhance the activity of CO oxidation reaction for the generation of optimal active Pt site.An innovative near-situ X-ray absorption fine structure(XAFS)technique was used to investigate the chemical state of central Pt atom during the reaction process,clearly demonstrating that the high oxidized state of Pt does harm to the activity for CO oxidation while the relatively reductive Pt exhibits high activity,and the different oxidized state and chemical environment of Pt during every process has been identified.Furthermore,the activity of our Pt/CeO_(2)catalyst is superior to that of most of the previous reports about CO catalytic oxidation by Pt based catalyst.Moreover,the optimal active species(Pt-O_(4))have been identified after hydrogen reduction,which could be a possible key strategy to control the oxidation of Pt.
基金supported by the Royal Academy of Engineering,United Kingdom
文摘An extensive study has been conducted on the proton exchange membrane fuel cells （PEMFCs） with reducing Pt loading. This is commonly achieved by developing methods to increase the utilization of the platinum in the catalyst layer of the electrodes. In this paper, a novel process of the catalyst layers was introduced and investigated. A mixture of carbon powder and Nafion solution was sprayed on the glassy carbon electrode （GCE） to form a thin carbon layer. Then Pt particles were deposited on the surface by reducing hexachloroplatinic （IV） acid hexahydrate with methanoic acid. SEM images showed a continuous Pt gradient profile among the thickness direction of the catalytic layer by the novel method. The Pt nanowires grown are in the size of 3 nm （diameter） x l0 nm （length） by high solution TEM image. The novel catalyst layer was characterized by cyclic voltammetry （CV） and scanning electron microscope （SEM） as compared with commercial Pt/C black and Pt catalyst layer obtained from sputtering. The results showed that the platinum nanoparticles deposited on the carbon powder were highly utilized as they directly faced the gas diffusion layer and offered easy access to reactants （oxygen or hydrogen）.
文摘1, 1'--Bis(benzylseleno)ferrocene and its platinum complex were synthesized. It was found that the platinum complex was efficient catalyst for the hydrosilylation of olefins with triethoxysilane.
基金financially supported by the National Natural Science Foundation of China(NSFC,Grant no.21503228)the Transformational Technologies for Clean Energy and Demonstration,Strategic Priority Research Program of the Chinese Academy of Sciences(Grant no.XDA21090203)。
文摘Fabrication of novel electrode architectures with nanostructured ultrathin catalyst layers is an effective strategy to improve catalyst utilization and enhance mass transport for polymer electrolyte membrane fuel cells (PEMFCs).Herein,we report the design and construction of a nanostructured ultrathin catalyst layer with ordered Pt nanotube arrays,which were obtained by a hard-template strategy based on ZnO,via hydrothermal synthesis and magnetron sputtering for PEMFC application.Because of the crystallographically preferential growth of Pt (111) facets,which was attributed to the structural effects of ZnO nanoarrays on the Pt nanotubes,the catalyst layers exhibit obviously higher electrochemical activity with remarkable enhancement of specific activity and mass transport compared with the state-of-the-art randomly distributed Pt/C catalyst layer.The PEMFC fabricated with the as-prepared catalyst layer composed of optimized Pt nanotubes with an average diameter of 90(±10) nm shows excellent performance with a peak power density of 6.0W/mgPt at 1 A/cm^2,which is 11.6%greater than that of the conventional Pt/C electrode.
基金This work was supported by the National Natural Science Foundation of China and the Natural Science Foundation of Hubei Province
文摘A modified method of preparing crown functionalized linear polysiloxane has been described.4'-allylbenzo-15-crown-5 was subjected to hydrosilylation with methyldichlorosilane,followed bypolycondensation with silanol-terminated polydimethylsiloxane to give the title crownfunctionalized linear polysiloxane. It was found that the polysiloxane could be coordinated withplatinum salt to form platinum complex, which could catalyze the hydrosilylation of olefins withtriethoxysilane efficiently.
文摘Silica-bound 15-Crown-5, 18-Crown-6 with a spacer of propyloxymethyl and their platinum complexes have been synthesized. It was found that they were efficient catalysts for the hydrosilylation of olefms with triethoxysilane in the temperature range of 60 to 130 ℃.
文摘The addition of platinum over the B2O3/TiO2-ZrO2 remarkably enhanced its catalytic stability in the vapor phase Beckmann rearrangement of cyclohexanone oxime under the carder gas of H2. The content of coke deposited on catalyst surface was decreased from 1.92% over the B2O3/TiO2-ZrO2 to 1.14% over the platinum promoted B2O3/TiO2-ZrO2 after reaction of six hours. This result indicates that the platinum added on the B2O3/TiO2-ZrO2 catalyst plays an important role in reducing the coke formation on the catalyst surface.
基金supported by the National High Technology Research and Development Program of China(863 Program,2015AA034603)the National Natural Science Foundation of China(21377008)Foundation on the Creative Research Team Construction Promotion Project of Beijing Municipal Institutions
文摘Three-dimensionally ordered macro-/mesoporous alumina（3DOM Al2O3）-supported cobalt oxide and platinum nanocatalysts（xPt/yCo3O4/3DOM Al2O3,Pt mass fraction（x%）= 0-1.4%,Co3O4 mass fraction（y%） = 0-9.2%） were prepared using poly（methyl methacrylate） templating,incipient wetness impregnation and polyvinyl alcohol-protected reduction.The resulting xPt/yCo3O4/3DOM Al2O3 samples displayed a high-quality 3DOM architecture with macropores（180-200 nm in diameter） and mesopores（4-6 nm in diameter） together with surface areas in the range of 94 to 102m^2/g.Using these techniques,Co3O4 nanoparticles（NPs,18.3 nm） were loaded on the 3DOM Al2O3 surface,after which Pt NPs（2.3-2.5 nm） were uniformly dispersed on theyCo3O4/3DOM Al2O3.The1.3Pt/8.9Co3O4/3DOM Al2O3 exhibited the best performance for toluene oxidation,with a T（90%） value（the temperature required to achieve 90%toluene conversion） of 160 ℃ at a space velocity of20000 mL g^（-1） h^（-1）.It is concluded that the excellent catalytic performance of the 1.3Pt/8.9Co3O4/3DOM Al2O3 is owing to well-dispersed Pt NPs,the high concentration of adsorbed oxygen species,good low-temperature reducibility,and strong interaction between the Pt and Co3O4 NPs,as well as the unique bimodal porous structure of the support.
基金supported by the National Natural Science Foundation of China (21476145)~~
文摘The Pt decorated Ni/C nanocatalysts were prepared for hydrogen oxidation reaction（HOR） in fuel cell.By regulating the contents of Pt and Ni in the catalyst,both the composition and the structure affected the electrochemical catalytic characteristics of the Pt-Ni/C catalysts.When the Pt mass content was 3.1% percent and that of Ni was 13.9% percent,the Pt-Ni/C-3 catalyst exhibited a larger electrochemically active surface area and a higher exchange current density toward HOR than those of pure supported platinum sample.Our study demonstrates a feasible approach for designing the more efficient catalysts with lower content of noble metal for HOR in fuel cell.
