Selective hydrogenation of phenol to cyclohexanone is intriguing in chemical industry.Though a few catalysts with promising performances have been developed in recent years,the basic principle for catalyst design is s...Selective hydrogenation of phenol to cyclohexanone is intriguing in chemical industry.Though a few catalysts with promising performances have been developed in recent years,the basic principle for catalyst design is still missing owing to the unclear catalytic mechanism.This work tries to unravel the mechanism of phenol hydro-genation and the reasons causing the selectivity discrepancy on noble metal catalysts under mild conditions.Results show that different reaction pathways always firstly converge to the formation of cyclohexanone under mild conditions.The selectivity discrepancy mainly depends on the activity for cyclohexanone sequential hy-drogenation,in which two factors are found to be responsible,i.e.the hydrogenation energy barrier and the competitive chemisorption between phenol and cyclohexanone,if the specific co-catalyzing effect of H 2 O on Ru is not considered.Based on the above results,a quantitative descriptor,E b(one/pl)/E a,in which E a can be further correlated to the d band center of the noble metal catalyst,is proposed by the first time to roughly evaluate and predict the selectivity to cyclohexanone for catalyst screening.展开更多
Most of volatile organic compounds （VOCs） are harmful to the atmosphere and human health. Cata‐lytic combustion is an effective way to eliminate VOCs. The key issue is the availability of high per‐formance catalys...Most of volatile organic compounds （VOCs） are harmful to the atmosphere and human health. Cata‐lytic combustion is an effective way to eliminate VOCs. The key issue is the availability of high per‐formance catalysts. Many catalysts including transition metal oxides, mixed metal oxides, and sup‐ported noble metals have been developed. Among these catalysts, the porous ones attract much attention. In this review, we focus on recent advances in the synthesis of ordered mesoporous and macroporous transition metal oxides, perovskites, and supported noble metal catalysts and their catalytic oxidation of VOCs. The porous catalysts outperformed their bulk counterparts. This excel‐lent catalytic performance was due to their high surface areas, high concentration of adsorbed oxy‐gen species, low temperature reducibility, strong interaction between noble metal and support and highly dispersed noble metal nanoparticles and unique porous structures. Catalytic oxidation of carbon monoxide over typical catalysts was also discussed. We made conclusive remarks and pro‐posed future work for the removal of VOCs.展开更多
Y zeolite supporting noble metal catalysts, as the important industrial catalysts for aromatics hydrogenation, have received increasing attention in recent years. Pd M/Y bimetallic catalysts, where M is non noble meta...Y zeolite supporting noble metal catalysts, as the important industrial catalysts for aromatics hydrogenation, have received increasing attention in recent years. Pd M/Y bimetallic catalysts, where M is non noble metal element, were prepared to investigate the effects of the addition of a second metal. Pd M/Y catalysts were evaluated under the following conditions: H 2 pressure 4.2 MPa, MHSV 4.0 h -1 , sulfur content in feed 3000 μg/g. The microreactor results indicated that the second metal remarkably affects the hydrogenation activity of Pd/Y catalysts. Among them, Cr and W improve the sulfur resistance of Pd/Y, but La, Mn, Mo and Ag make the sulfur resistance worse and the second metals have no evident influence on product selectivity and acidic properties of the catalysts.展开更多
Formaldehyde（HCHO）is carcinogenic and teratogenic,and is therefore a serious danger to human health.It also adversely affects air quality.Catalytic oxidation is an efficient technique for removing HCHO.The developme...Formaldehyde（HCHO）is carcinogenic and teratogenic,and is therefore a serious danger to human health.It also adversely affects air quality.Catalytic oxidation is an efficient technique for removing HCHO.The development of highly efficient and stable catalysts that can completely convert HCHO at low temperatures,even room temperature,is important.Supported Pt and Pd catalysts can completely convert HCHO at room temperature,but their industrial applications are limited because they are expensive.The catalytic activities in HCHO oxidation of transition-metal oxide catalysts such as manganese and cobalt oxides with unusual morphologies are better than those of traditional MnO2,Co3O4,or other metal oxides.This is attributed to their specific structures,high specific surface areas,and other factors such as active phase,reducibility,and amount of surface active oxygens.Such catalysts with various morphologies have great potential and can also be used as catalyst supports.The loading of relatively cheap Ag or Au on transition-metal oxides with special morphologies potentially improves the catalytic activity in HCHO removal at room temperature.The preparation and development of new nanocatalysts with various morphologies and structures is important for HCHO removal.In this paper,research progress on precious-metal and transition-metal oxide catalyst systems for HCHO oxidation is reviewed; topics such as oxidation properties,structure–activity relationships,and factors influencing the catalytic activity and reaction mechanism are discussed.Future prospects and directions for the development of such catalysts are also covered.展开更多
Microbial fuel cells(MFCs)have a simple structure and excellent pollutant treatment and power generation performance.However,the slow kinetics of the oxygen reduction reaction(ORR)at the MFC cathode limit power genera...Microbial fuel cells(MFCs)have a simple structure and excellent pollutant treatment and power generation performance.However,the slow kinetics of the oxygen reduction reaction(ORR)at the MFC cathode limit power generation.The electrochemical performance of MFCs can be improved through electrocatalysis.Thus far,metal-based catalysts have shown astonishing results in the field of electrocatalysis,enabling MFC devices to demonstrate power generation capabilities comparable to those of Pt,thus showing enormous potential.This article reviews the research progress of meta-based MFC cathode ORR catalysts,including the ORR reaction mechanism of MFC,different types of catalysts,and preparation strategies.The catalytic effects of different catalysts in MFC are compared and summarized.Before discussing the practical application and expanded manufacturing of catalysts,we summarize the key challenges that must be addressed when using metal-based catalysts in MFC,with the aim of providing a scientific direction for the future development of advanced materials.展开更多
The meso-Co3O4 and AgxAuyPd/meso-Co3O4 catalysts were prepared using the KIT-6-templating and polyvinyl alcohol-protected NaBH4 reduction methods,respectively.Various techniques were used to characterize physicochemic...The meso-Co3O4 and AgxAuyPd/meso-Co3O4 catalysts were prepared using the KIT-6-templating and polyvinyl alcohol-protected NaBH4 reduction methods,respectively.Various techniques were used to characterize physicochemical properties of these materials.Catalytic performance of the samples was evaluated for methanol combustion.The cubically crystallized Co3O4 support displayed a three-dimensionally ordered mesoporous structure.The supported noble metal nanoparticles(NPs)possessed a surface area of 115.125 m^2/g,with the noble NPs(average size=2.8.4.5 nm)being uniformly dispersed on the surface of meso-Co3O4.Among all of the samples,0.68 wt%Ag0.75Au1.14Pd/meso-Co3O4 showed the highest catalytic activity(T50%=100℃and T90%=112℃at a space velocity of 80000 mL(g^–1 h^–1).The partial deactivation of the 0.68 wt%Ag0.75Au1.14Pd/meso-Co3O4 sample due to water vapor or carbon dioxide introduction was reversible.It is concluded that the good catalytic performance of 0.68 wt%Ag0.75Au1.14Pd/meso-Co3O4 was associated with its highly dispersed Ag0.75Au1.14Pd alloy NPs,high adsorbed oxygen species concentration,good low-temperature reducibility,and strong interaction between Ag0.75Au1.14Pd alloy NPs and meso-Co3O4.展开更多
Electrochemical CO_(2) reduction reaction (CO_(2) RR) offers a practical solution to current global greenhouse effect by converting excessive CO_(2) into value-added chemicals or fuels. Noble metal-based nanomaterials...Electrochemical CO_(2) reduction reaction (CO_(2) RR) offers a practical solution to current global greenhouse effect by converting excessive CO_(2) into value-added chemicals or fuels. Noble metal-based nanomaterials have been considered as efficient catalysts for the CO_(2) RR owing to their high catalytic activity, long-term stability and superior selectivity to targeted products. On the other hand, they are usually loaded on different support materials in order to minimize their usage and maximize the utilization because of high price and limited reserve. The strong metal-support interaction (MSI) between the metal and substrate plays an important role in affecting the CO_(2) RR performance. In this review, we mainly focus on different types of support materials (e.g., oxides, carbons, ligands, alloys and metal carbides) interacting with noble metal as electrocatalysts for CO_(2) RR. Moreover, the positive effects about MSI for boosting the CO_(2) RR performance via regulating the adsorption strength, electronic structure, coordination environment and binding energy are presented. Lastly, emerging challenges and future opportunities on noble metal electrocatalysts with strong MSI are discussed.展开更多
Volatile organic compounds(VOCs),methane,carbon monoxide,soot,automotive exhaust,and nitrogen oxides are harmful to the atmosphere and human health.It is urgent to strictly control their emissions.Heterogeneous cataly...Volatile organic compounds(VOCs),methane,carbon monoxide,soot,automotive exhaust,and nitrogen oxides are harmful to the atmosphere and human health.It is urgent to strictly control their emissions.Heterogeneous catalysis is an effective pathway for the removal of these pollutants,and the critical issue is the development of novel and high-performance catalysts.In this review,we briefly summarize the preparation methods,physicochemical properties,catalytic activities,and related reaction mechanisms for the above pollutants removal of the rare earth oxides,mixed rare earth oxide,rare earth oxidesupported noble metal,and mixed rare earth oxide-supported noble metal catalysts that have been investigated by our group and other researchers.It was found that catalytic performance was associated with the factors,such as specific surface area,pore structure,particle size and dispersion,adsorbed oxygen species concentration,reducibility,reactant activation ability or interaction between metal nanoparticles and support.Furthermore,we also envision the development trend of such a topic in future work.展开更多
Ordered mesoporous Mn2O3 (meso‐Mn2O3) and meso‐Mn2O3‐supported Pd, Pt, and Pd‐Pt alloy x(PdyPt)/meso‐Mn2O3; x = (0.10?1.50) wt%; Pd/Pt molar ratio (y) = 4.9?5.1 nanocatalysts were prepared using KIT‐6‐templated...Ordered mesoporous Mn2O3 (meso‐Mn2O3) and meso‐Mn2O3‐supported Pd, Pt, and Pd‐Pt alloy x(PdyPt)/meso‐Mn2O3; x = (0.10?1.50) wt%; Pd/Pt molar ratio (y) = 4.9?5.1 nanocatalysts were prepared using KIT‐6‐templated and poly(vinyl alcohol)‐protected reduction methods, respectively.The meso‐Mn2O3 had a high surface area, i.e., 106 m2/g, and a cubic crystal structure. Noble‐metalnanoparticles (NPs) of size 2.1?2.8 nm were uniformly dispersed on the meso‐Mn2O3 surfaces. AlloyingPd with Pt enhanced the catalytic activity in methane combustion; 1.41(Pd5.1Pt)/meso‐Mn2O3gave the best performance; T10%, T50%, and T90% (the temperatures required for achieving methaneconversions of 10%, 50%, and 90%) were 265, 345, and 425 °C, respectively, at a space velocity of20000 mL/(g?h). The effects of SO2, CO2, H2O, and NO on methane combustion over1.41(Pd5.1Pt)/meso‐Mn2O3 were also examined. We conclude that the good catalytic performance of1.41(Pd5.1Pt)/meso‐Mn2O3 is associated with its high‐quality porous structure, high adsorbed oxygen species concentration, good low‐temperature reducibility, and strong interactions between Pd‐Pt alloy NPs and the meso‐Mn2O3 support.展开更多
Catalytic treatments of VOCs at normal temperature can greatly reduce the cost and temperature of processing,and improve the safety factor in line with the requirements of green chemistry.Activated carbon fiber(ACF)wa...Catalytic treatments of VOCs at normal temperature can greatly reduce the cost and temperature of processing,and improve the safety factor in line with the requirements of green chemistry.Activated carbon fiber(ACF)was pretreated with 10%H_(2)SO_(4)by single factor optimization to increase specific surface area and pore volume obviously.The catalytic ozonation performance of ACF loaded with Au,Ag,Pt and Pd noble metals on ethyl acetate was investigated and Pd/ACF was selected as the optimal catalyst which had certain stability.Pd is uniformly distributed on the surface of ACF,and Palladium mainly exists in the form of Pd0 with a amount of Pd+2.The specific surface area of the catalysts gradually decreases as the loading increases.The activation energy of ethyl acetate calculated by Arrhenius equation is 113 kJ mol 1.With 1%Pd loading and the concentration ratio of ozone to ethyl acetate is 3:1,catalytic ozonation performance is maximized and the conversion rate of ethyl acetate reached to 60%in 3050℃Cat 15,00030,000 h^1.展开更多
Ruthenium(Ru)has been recognized as a prospective candidate to substitute platinum catalysts in water-splitting-based hydrogen production.However,minimizing the Ru contents,optimizing the water dissociation energy of ...Ruthenium(Ru)has been recognized as a prospective candidate to substitute platinum catalysts in water-splitting-based hydrogen production.However,minimizing the Ru contents,optimizing the water dissociation energy of Ru sites,and enhancing the long-term stability are extremely required,but still face a great challenge.Here,we report on creating tungsten oxide-anchored Ru clusters(Ru-WO_(x))with electron-rich and anti-corrosive microenvironments for efficient and robust seawater splitting.Benefiting from the abundant oxygen vacancy structure in tungsten oxide support,the Ru-WO_(x)exhibits strong Ru-O and Ru-W bonds at the interface.Our study elucidates that the strong Ru-O bonds in Ru-WO_(x)may accelerate the water dissociation kinetics,and the Ru-W bonds will lead to the strong metal-support interaction and electrons transfer fromWto Ru.The optimal Ru-WO_(x)catalysts exhibit a low overpotential of 29 and 218mVat the current density of 10 mA cm^(−2) in alkaline and seawater media,respectively.The outstanding long-term stability discloses that the Ru-WO_(x)catalysts own efficient corrosion resistance in seawater electrolysis.We believe that thiswork offers new insights into the essential roles of electron-rich and anti-corrosivemicroenvironments in Ru-based catalysts and provide a new pathway to design efficient and robust cathodes for seawater splitting.展开更多
Mo-modified Pd/Al2O3catalysts were prepared by an impregnation method and tested for the catalytic combustion of benzene. The catalysts were characterized by N2 isothermal adsorption, X-ray diffraction（XRD）, X-ray p...Mo-modified Pd/Al2O3catalysts were prepared by an impregnation method and tested for the catalytic combustion of benzene. The catalysts were characterized by N2 isothermal adsorption, X-ray diffraction（XRD）, X-ray photoelectron spectroscopy（XPS）, temperatureprogrammed desorption of NH3（NH3-TPD）, H2temperature-programmed reduction（H2-TPR）, and high-angle annular dark-field scanning transmission electron microscopy（HAADF-STEM）. The results showed that the addition of Mo effectively improved the activity and stability of the Pd/Al2O3catalyst by increasing the dispersion of Pd active components, changing the partial oxidation state of palladium and increasing the oxygen species concentration on the surface of catalyst. In the case of the Pd-Mo/Al2O3catalyst,benzene conversion of 90% was obtained at temperatures as low as 190°C, which was 45°C lower than that for similar performance with the Pd/Al2O3catalyst. Moreover, the 1.0% Pd-5% Mo/Al2O3catalyst was more active than the 2.0% Pd/Al2O3catalyst. It was concluded that Pd and Mo have a synergistic effect in benzene catalytic combustion.展开更多
基金This work was supported by Financial support from the National Natural Science Foundation of China(21908189,21872121)the National Key R&D Program of China(2016YFA0202900)+1 种基金the Key Program supportedby theNaturalScience Foundationof ZhejiangProvince,China(LZ18B060002)the Key R&D Project of Zhejiang Province(2020C01133).
文摘Selective hydrogenation of phenol to cyclohexanone is intriguing in chemical industry.Though a few catalysts with promising performances have been developed in recent years,the basic principle for catalyst design is still missing owing to the unclear catalytic mechanism.This work tries to unravel the mechanism of phenol hydro-genation and the reasons causing the selectivity discrepancy on noble metal catalysts under mild conditions.Results show that different reaction pathways always firstly converge to the formation of cyclohexanone under mild conditions.The selectivity discrepancy mainly depends on the activity for cyclohexanone sequential hy-drogenation,in which two factors are found to be responsible,i.e.the hydrogenation energy barrier and the competitive chemisorption between phenol and cyclohexanone,if the specific co-catalyzing effect of H 2 O on Ru is not considered.Based on the above results,a quantitative descriptor,E b(one/pl)/E a,in which E a can be further correlated to the d band center of the noble metal catalyst,is proposed by the first time to roughly evaluate and predict the selectivity to cyclohexanone for catalyst screening.
基金supported by the National High Technology Research and Development Program (863 Program,2015AA034603)the National Natural Science Foundation of China (21377008,201077007,20973017)+1 种基金Foundation on the Creative Research Team Construction Promotion Project of Beijing Municipal InstitutionsScientific Research Base Construction-Science and Technology Creation Platform National Materials Research Base Construction~~
文摘Most of volatile organic compounds （VOCs） are harmful to the atmosphere and human health. Cata‐lytic combustion is an effective way to eliminate VOCs. The key issue is the availability of high per‐formance catalysts. Many catalysts including transition metal oxides, mixed metal oxides, and sup‐ported noble metals have been developed. Among these catalysts, the porous ones attract much attention. In this review, we focus on recent advances in the synthesis of ordered mesoporous and macroporous transition metal oxides, perovskites, and supported noble metal catalysts and their catalytic oxidation of VOCs. The porous catalysts outperformed their bulk counterparts. This excel‐lent catalytic performance was due to their high surface areas, high concentration of adsorbed oxy‐gen species, low temperature reducibility, strong interaction between noble metal and support and highly dispersed noble metal nanoparticles and unique porous structures. Catalytic oxidation of carbon monoxide over typical catalysts was also discussed. We made conclusive remarks and pro‐posed future work for the removal of VOCs.
文摘Y zeolite supporting noble metal catalysts, as the important industrial catalysts for aromatics hydrogenation, have received increasing attention in recent years. Pd M/Y bimetallic catalysts, where M is non noble metal element, were prepared to investigate the effects of the addition of a second metal. Pd M/Y catalysts were evaluated under the following conditions: H 2 pressure 4.2 MPa, MHSV 4.0 h -1 , sulfur content in feed 3000 μg/g. The microreactor results indicated that the second metal remarkably affects the hydrogenation activity of Pd/Y catalysts. Among them, Cr and W improve the sulfur resistance of Pd/Y, but La, Mn, Mo and Ag make the sulfur resistance worse and the second metals have no evident influence on product selectivity and acidic properties of the catalysts.
基金supported by the National Natural Science Foundation of China(21325731,51478241,21221004)~~
文摘Formaldehyde（HCHO）is carcinogenic and teratogenic,and is therefore a serious danger to human health.It also adversely affects air quality.Catalytic oxidation is an efficient technique for removing HCHO.The development of highly efficient and stable catalysts that can completely convert HCHO at low temperatures,even room temperature,is important.Supported Pt and Pd catalysts can completely convert HCHO at room temperature,but their industrial applications are limited because they are expensive.The catalytic activities in HCHO oxidation of transition-metal oxide catalysts such as manganese and cobalt oxides with unusual morphologies are better than those of traditional MnO2,Co3O4,or other metal oxides.This is attributed to their specific structures,high specific surface areas,and other factors such as active phase,reducibility,and amount of surface active oxygens.Such catalysts with various morphologies have great potential and can also be used as catalyst supports.The loading of relatively cheap Ag or Au on transition-metal oxides with special morphologies potentially improves the catalytic activity in HCHO removal at room temperature.The preparation and development of new nanocatalysts with various morphologies and structures is important for HCHO removal.In this paper,research progress on precious-metal and transition-metal oxide catalyst systems for HCHO oxidation is reviewed; topics such as oxidation properties,structure–activity relationships,and factors influencing the catalytic activity and reaction mechanism are discussed.Future prospects and directions for the development of such catalysts are also covered.
基金supported by the National Natural Science Foundation of China(Nos.52170019 and 51973015)the Fundamental Research Funds for the Central Universities(No.06500100)the“Ten thousand plan”-National High-level Personnel of Special Support Program.National Environmental and Energy Science and Technology International Cooperation Base.
文摘Microbial fuel cells(MFCs)have a simple structure and excellent pollutant treatment and power generation performance.However,the slow kinetics of the oxygen reduction reaction(ORR)at the MFC cathode limit power generation.The electrochemical performance of MFCs can be improved through electrocatalysis.Thus far,metal-based catalysts have shown astonishing results in the field of electrocatalysis,enabling MFC devices to demonstrate power generation capabilities comparable to those of Pt,thus showing enormous potential.This article reviews the research progress of meta-based MFC cathode ORR catalysts,including the ORR reaction mechanism of MFC,different types of catalysts,and preparation strategies.The catalytic effects of different catalysts in MFC are compared and summarized.Before discussing the practical application and expanded manufacturing of catalysts,we summarize the key challenges that must be addressed when using metal-based catalysts in MFC,with the aim of providing a scientific direction for the future development of advanced materials.
基金supported by the National Natural Science Foundation of China(21677004,21876006,and 21622701)the National High Technology Research and Development Program of China(863 Program,2015AA034603)~~
文摘The meso-Co3O4 and AgxAuyPd/meso-Co3O4 catalysts were prepared using the KIT-6-templating and polyvinyl alcohol-protected NaBH4 reduction methods,respectively.Various techniques were used to characterize physicochemical properties of these materials.Catalytic performance of the samples was evaluated for methanol combustion.The cubically crystallized Co3O4 support displayed a three-dimensionally ordered mesoporous structure.The supported noble metal nanoparticles(NPs)possessed a surface area of 115.125 m^2/g,with the noble NPs(average size=2.8.4.5 nm)being uniformly dispersed on the surface of meso-Co3O4.Among all of the samples,0.68 wt%Ag0.75Au1.14Pd/meso-Co3O4 showed the highest catalytic activity(T50%=100℃and T90%=112℃at a space velocity of 80000 mL(g^–1 h^–1).The partial deactivation of the 0.68 wt%Ag0.75Au1.14Pd/meso-Co3O4 sample due to water vapor or carbon dioxide introduction was reversible.It is concluded that the good catalytic performance of 0.68 wt%Ag0.75Au1.14Pd/meso-Co3O4 was associated with its highly dispersed Ag0.75Au1.14Pd alloy NPs,high adsorbed oxygen species concentration,good low-temperature reducibility,and strong interaction between Ag0.75Au1.14Pd alloy NPs and meso-Co3O4.
基金This work was financially supported by National Key Research and Development Program(No.2018YFB1502503)and Sichuan Science and Technology Program(No.2020YJ0299).
文摘Electrochemical CO_(2) reduction reaction (CO_(2) RR) offers a practical solution to current global greenhouse effect by converting excessive CO_(2) into value-added chemicals or fuels. Noble metal-based nanomaterials have been considered as efficient catalysts for the CO_(2) RR owing to their high catalytic activity, long-term stability and superior selectivity to targeted products. On the other hand, they are usually loaded on different support materials in order to minimize their usage and maximize the utilization because of high price and limited reserve. The strong metal-support interaction (MSI) between the metal and substrate plays an important role in affecting the CO_(2) RR performance. In this review, we mainly focus on different types of support materials (e.g., oxides, carbons, ligands, alloys and metal carbides) interacting with noble metal as electrocatalysts for CO_(2) RR. Moreover, the positive effects about MSI for boosting the CO_(2) RR performance via regulating the adsorption strength, electronic structure, coordination environment and binding energy are presented. Lastly, emerging challenges and future opportunities on noble metal electrocatalysts with strong MSI are discussed.
基金Project supported by National Natural Science Foundation of China(21677004,21876006,21622701)National Natural Science Committee of China-Liaoning Provincial People’s Government Joint Fund(U1908204)Foundation on the Creative Research Team Construction Promotion Project of Beijing Municipal Institutions(IDHT20190503)。
文摘Volatile organic compounds(VOCs),methane,carbon monoxide,soot,automotive exhaust,and nitrogen oxides are harmful to the atmosphere and human health.It is urgent to strictly control their emissions.Heterogeneous catalysis is an effective pathway for the removal of these pollutants,and the critical issue is the development of novel and high-performance catalysts.In this review,we briefly summarize the preparation methods,physicochemical properties,catalytic activities,and related reaction mechanisms for the above pollutants removal of the rare earth oxides,mixed rare earth oxide,rare earth oxidesupported noble metal,and mixed rare earth oxide-supported noble metal catalysts that have been investigated by our group and other researchers.It was found that catalytic performance was associated with the factors,such as specific surface area,pore structure,particle size and dispersion,adsorbed oxygen species concentration,reducibility,reactant activation ability or interaction between metal nanoparticles and support.Furthermore,we also envision the development trend of such a topic in future work.
基金supported by the Ph.D.Program Foundation of Ministry of Education of China(20131103110002)the NNSF of China(21377008)+2 种基金National High Technology Research and Development Program(863 Program,2015AA034603)Foundation on the Creative Research Team Con-struction Promotion Project of Beijing Municipal InstitutionsScientific Research Base Construction-Science and Technology Creation Plat-form-National Materials Research Base Construction~~
文摘Ordered mesoporous Mn2O3 (meso‐Mn2O3) and meso‐Mn2O3‐supported Pd, Pt, and Pd‐Pt alloy x(PdyPt)/meso‐Mn2O3; x = (0.10?1.50) wt%; Pd/Pt molar ratio (y) = 4.9?5.1 nanocatalysts were prepared using KIT‐6‐templated and poly(vinyl alcohol)‐protected reduction methods, respectively.The meso‐Mn2O3 had a high surface area, i.e., 106 m2/g, and a cubic crystal structure. Noble‐metalnanoparticles (NPs) of size 2.1?2.8 nm were uniformly dispersed on the meso‐Mn2O3 surfaces. AlloyingPd with Pt enhanced the catalytic activity in methane combustion; 1.41(Pd5.1Pt)/meso‐Mn2O3gave the best performance; T10%, T50%, and T90% (the temperatures required for achieving methaneconversions of 10%, 50%, and 90%) were 265, 345, and 425 °C, respectively, at a space velocity of20000 mL/(g?h). The effects of SO2, CO2, H2O, and NO on methane combustion over1.41(Pd5.1Pt)/meso‐Mn2O3 were also examined. We conclude that the good catalytic performance of1.41(Pd5.1Pt)/meso‐Mn2O3 is associated with its high‐quality porous structure, high adsorbed oxygen species concentration, good low‐temperature reducibility, and strong interactions between Pd‐Pt alloy NPs and the meso‐Mn2O3 support.
基金the National Key R&D Program of the Ministry of Science and Technology,China(Grant No.2018YFC0705304)and the Key Scientific and Technological Support Projects,Tianjin City,China(Grant No.19YFZCSF01090).
文摘Catalytic treatments of VOCs at normal temperature can greatly reduce the cost and temperature of processing,and improve the safety factor in line with the requirements of green chemistry.Activated carbon fiber(ACF)was pretreated with 10%H_(2)SO_(4)by single factor optimization to increase specific surface area and pore volume obviously.The catalytic ozonation performance of ACF loaded with Au,Ag,Pt and Pd noble metals on ethyl acetate was investigated and Pd/ACF was selected as the optimal catalyst which had certain stability.Pd is uniformly distributed on the surface of ACF,and Palladium mainly exists in the form of Pd0 with a amount of Pd+2.The specific surface area of the catalysts gradually decreases as the loading increases.The activation energy of ethyl acetate calculated by Arrhenius equation is 113 kJ mol 1.With 1%Pd loading and the concentration ratio of ozone to ethyl acetate is 3:1,catalytic ozonation performance is maximized and the conversion rate of ethyl acetate reached to 60%in 3050℃Cat 15,00030,000 h^1.
基金National Natural Science Foundation of China,Grant/Award Number:52273269Sichuan Science and Technology Program,Grant/Award Numbers:2023YFH0027,2023YFH0008+3 种基金Fundamental Research Funds for the Central UniversitiesState Key Laboratory of Polymer Materials Engineering,Grant/Award Numbers:sklpme2022-3-07,sklpme2021-4-02GRF,Grant/Award Number:CityU11308923The Basic Research Project from Shenzhen Science and Technology Innovation Committee,Grant/Award Number:JCYJ20210324134012034。
文摘Ruthenium(Ru)has been recognized as a prospective candidate to substitute platinum catalysts in water-splitting-based hydrogen production.However,minimizing the Ru contents,optimizing the water dissociation energy of Ru sites,and enhancing the long-term stability are extremely required,but still face a great challenge.Here,we report on creating tungsten oxide-anchored Ru clusters(Ru-WO_(x))with electron-rich and anti-corrosive microenvironments for efficient and robust seawater splitting.Benefiting from the abundant oxygen vacancy structure in tungsten oxide support,the Ru-WO_(x)exhibits strong Ru-O and Ru-W bonds at the interface.Our study elucidates that the strong Ru-O bonds in Ru-WO_(x)may accelerate the water dissociation kinetics,and the Ru-W bonds will lead to the strong metal-support interaction and electrons transfer fromWto Ru.The optimal Ru-WO_(x)catalysts exhibit a low overpotential of 29 and 218mVat the current density of 10 mA cm^(−2) in alkaline and seawater media,respectively.The outstanding long-term stability discloses that the Ru-WO_(x)catalysts own efficient corrosion resistance in seawater electrolysis.We believe that thiswork offers new insights into the essential roles of electron-rich and anti-corrosivemicroenvironments in Ru-based catalysts and provide a new pathway to design efficient and robust cathodes for seawater splitting.
基金supported by the National High-Tech Research and Development Program (863) of China (No. 2008AA06XK1480855)
文摘Mo-modified Pd/Al2O3catalysts were prepared by an impregnation method and tested for the catalytic combustion of benzene. The catalysts were characterized by N2 isothermal adsorption, X-ray diffraction（XRD）, X-ray photoelectron spectroscopy（XPS）, temperatureprogrammed desorption of NH3（NH3-TPD）, H2temperature-programmed reduction（H2-TPR）, and high-angle annular dark-field scanning transmission electron microscopy（HAADF-STEM）. The results showed that the addition of Mo effectively improved the activity and stability of the Pd/Al2O3catalyst by increasing the dispersion of Pd active components, changing the partial oxidation state of palladium and increasing the oxygen species concentration on the surface of catalyst. In the case of the Pd-Mo/Al2O3catalyst,benzene conversion of 90% was obtained at temperatures as low as 190°C, which was 45°C lower than that for similar performance with the Pd/Al2O3catalyst. Moreover, the 1.0% Pd-5% Mo/Al2O3catalyst was more active than the 2.0% Pd/Al2O3catalyst. It was concluded that Pd and Mo have a synergistic effect in benzene catalytic combustion.
