Developing an efficiently supported Cu-based catalyst with promoters to substitute the existing non-supported Cu-based catalysts is highly desirable to the Rochow-Müller reaction. Using a simple ball-milling meth...Developing an efficiently supported Cu-based catalyst with promoters to substitute the existing non-supported Cu-based catalysts is highly desirable to the Rochow-Müller reaction. Using a simple ball-milling method and CeO_(2) support, we prepared a high-performance CuO-ZnO-P-Sn/CeO_(2) catalyst by integrating highly dispersed multicomponent promoters of ZnO, Sn, and P with the active component CuO. This catalyst shows a significantly enhanced dimethyldichlorosilane selectivity because these promoters can substantially increase the Cu+ content and the formation of an active CuxSi phase. This work provides a new approach to efficiently designing Cu-based catalysts for the Rochow-Müller reaction.展开更多
Cu-based catalysts have been extensively used in methanol steam reforming(MSR)reactions because of their low cost and high effi ciency.ZnO is often used in commercial Cu-based catalysts as both a structural and an ele...Cu-based catalysts have been extensively used in methanol steam reforming(MSR)reactions because of their low cost and high effi ciency.ZnO is often used in commercial Cu-based catalysts as both a structural and an electronic promoter to stabilize metal Cu nanoparticles and modify metal–support interfaces.Still,the further addition of chemical promoters is essential to further enhance the MSR reaction performance of the Cu/ZnO catalyst.In this work,CeO_(2)-doped Cu/ZnO catalysts were prepared using the coprecipitation method,and the eff ects of CeO_(2)on Cu-based catalysts were systematically investigated.Doping with appropriate CeO_(2)amounts could stabilize small Cu nanoparticles through a strong interaction between CeO_(2)and Cu,leading to the formation of more Cu+–ZnO x interfacial sites.However,higher CeO_(2)contents resulted in the formation of larger Cu nanoparticles and an excess of Cu+–CeO x interfacial sites.Consequently,the Cu/5CeO_(2)/ZnO catalyst with maximal Cu–ZnO interfaces exhibited the highest H 2 production rate of 94.6 mmolH2/(gcat·h),which was 1.5 and 10.2 times higher than those of Cu/ZnO and Cu/CeO_(2),respectively.展开更多
Developing high-performance ammonia decomposition catalysts for preparing COx-free hydrogen shows great practical significance.Herein,CeO_(2) is used as a promoter to modulate the metal-support interaction to enhance ...Developing high-performance ammonia decomposition catalysts for preparing COx-free hydrogen shows great practical significance.Herein,CeO_(2) is used as a promoter to modulate the metal-support interaction to enhance the catalytic performance of Ru/Al_(2)O_(3) catalysts.A series of 1Ru/xCe-10AI(x=0.5,1,or 3)catalysts was prepared by a facile colloidal deposition method.We find that the optimized 1 Ru/1Ce-10Al catalyst exhibits excellent activity for the decomposition of ammonia with a very high hydrogen yield of7097 mmolH2/(gRu·min)at 450℃.It is confirmed that Ru species are highly dispersed on the support surface as stable small clusters(~1.3 nm).More importantly,due to the interaction between Ru species and partially reduced CeO_(2-x),the electron density of Ru species is increased,which is beneficial to the high activity of the 1 Ru/xCe-10Al catalysts.This work paves a way to construct high-efficiency ammonia decomposition catalysts modified by CeO_(2).展开更多
CeO_(2)/g-C_(3)N_(4)photocatalysts have attracted tremendous attention in the photocatalytic degradation of organic pollutants.The design and construction of highly active CeO_(2)/g-C_(3)N_(4)photocatalysts without ha...CeO_(2)/g-C_(3)N_(4)photocatalysts have attracted tremendous attention in the photocatalytic degradation of organic pollutants.The design and construction of highly active CeO_(2)/g-C_(3)N_(4)photocatalysts without harsh conditions are still challenging.Herein,highly dispersed CeO_(2-x)nanoparticles with rich oxygen vacancies were successfully precipitated on the surface of g-C_(3)N_(4)under mild conditions.The fabricated CeO_(2-x)/g-C_(3)N_(4)exhibits remarkable activity and stability for photocatalytic degradation of MO pollutant.The optimal rate constant of MO degradation over CeO_(2-x)/g-C_(3)N_(4)is about 0.031 min^(-1),which is three times higher than that of g-C_(3)N_(4).A negligible activity decrease is observed after three cycling runs.The enhanced catalytic performance can be ascribed to the excellent dispersion of CeO_(2-x)with rich oxygen vacancies that benefit O_(2)adsorption and visible light absorption.In addition,the proper band alignment between CeO_(2-x)and gC_(3)N_(4)is conducive to the highly efficient separation of photogenerated electron-hole pairs.展开更多
Graphitic carbon nitride(g-C_(3)N_(4))-based materials are regarded as one of the most potential photocatalysts for utilizing solar energy.In this work,we reported a facile one step in-situ hydrothermal-roasting metho...Graphitic carbon nitride(g-C_(3)N_(4))-based materials are regarded as one of the most potential photocatalysts for utilizing solar energy.In this work,we reported a facile one step in-situ hydrothermal-roasting method for preparing honeycomb-like g-C_(3)N_(4)/CeO_(2) nanosheets with abundant oxygen vacancies(g-C_(3)N_(4)/CeO_(2)-x).The hydrothermal-roasting and incomplete-sealed state can(i)generate an in-situ reducing atmosphere(CO,N2,NH3) to tune the concentration of oxygen vacancies in CeO_(2);(ii) beneficial to prevent continuous growth of g-C_(3)N_(4) and results in honeycomb-like g-C_(3)N_(4)/CeO_(2)-x hybrid nanosheets.What is more,the g-C_(3)N_(4)/CeO_(2)-x photocatalyst exhibited extended photoresponse range,increased specific surface area and obviously enhanced separation efficiency of photogenerated electron-hole pairs.As a proof-of-concept application,the optimized g-C_(3)N_(4)/CeO_(2)-xnanosheets could achieve 98% removal efficiency for Cr(Ⅵ) under visible light irradiation(λ≥420 nm)within 2.5 h,which is significantly better than those of pure g-C_(3)N_(4) and CeO_(2).This work provides a new idea for more rationally designing and constructing g-C_(3)N_(4)-based catalysts for efficient extended photochemical application.展开更多
Rational design and performance promotion are eternal topics and ultimate goals in catalyst preparation.In contrast,trial–and–error is still the common method people take.Therefore,it is important to develop methods...Rational design and performance promotion are eternal topics and ultimate goals in catalyst preparation.In contrast,trial–and–error is still the common method people take.Therefore,it is important to develop methods to intrinsically enhance the performance of catalysts.The most effective solutions are the one from a kinetic perspective based on clear knowledge of the reaction mechanism.This paper describes rate-determining step cognition and modulation to promote CO oxidation on highly dispersed Pt on CeO_(2).The different degrees of metal–support interactions due to variation of hydroxyl density of support could alter the structure of active species and the ability of oxygen activation apparently,further shift the rate-determining step from oxygen activation to oxygen reverse spillover kinetically.The transformation of rate-determining step could enhance the intrinsic activity significantly,and decrease the T_(50) approximately 140℃.The findings of this research exemplify the universal and effective method of performance elevation by rate-determining step modulation,which is promising for application in different systems.展开更多
基金support from the National Natural Science Foundation of China(Nos.21978299 and 21878301)supported by the Open Research Fund of State Key Laboratory of Multiphase Complex Systems(MPCS-2021-D-08)+2 种基金GRINM Group(G12620213102035)Y.J.thanks the financial support from the Outstanding Youth Cultivation Program of Beijing Technology and Business University(No.19008021144)the Research Foundation for Advanced Talents of Beijing Technology and Business University(No.19008020159).
文摘Developing an efficiently supported Cu-based catalyst with promoters to substitute the existing non-supported Cu-based catalysts is highly desirable to the Rochow-Müller reaction. Using a simple ball-milling method and CeO_(2) support, we prepared a high-performance CuO-ZnO-P-Sn/CeO_(2) catalyst by integrating highly dispersed multicomponent promoters of ZnO, Sn, and P with the active component CuO. This catalyst shows a significantly enhanced dimethyldichlorosilane selectivity because these promoters can substantially increase the Cu+ content and the formation of an active CuxSi phase. This work provides a new approach to efficiently designing Cu-based catalysts for the Rochow-Müller reaction.
基金This work was supported by the National Key R&D Program of China(2022YFB3805504),National Natural Science Foundation of China(22078089)China Postdoctoral Science Foundation(2023M731081)+3 种基金Shanghai Pilot Program for Basic Research(22TQ1400100-7)the Basic Research Program of Science and Technology Commission of Shanghai Municipality(22JC1400600)Open Foundation of Shanghai Jiao Tong University Shaoxing Research Institute of Renewable Energy and Molecular Engineering(Grant No.JDSX2022046)Shanghai Super Postdoctoral Fellow.
文摘Cu-based catalysts have been extensively used in methanol steam reforming(MSR)reactions because of their low cost and high effi ciency.ZnO is often used in commercial Cu-based catalysts as both a structural and an electronic promoter to stabilize metal Cu nanoparticles and modify metal–support interfaces.Still,the further addition of chemical promoters is essential to further enhance the MSR reaction performance of the Cu/ZnO catalyst.In this work,CeO_(2)-doped Cu/ZnO catalysts were prepared using the coprecipitation method,and the eff ects of CeO_(2)on Cu-based catalysts were systematically investigated.Doping with appropriate CeO_(2)amounts could stabilize small Cu nanoparticles through a strong interaction between CeO_(2)and Cu,leading to the formation of more Cu+–ZnO x interfacial sites.However,higher CeO_(2)contents resulted in the formation of larger Cu nanoparticles and an excess of Cu+–CeO x interfacial sites.Consequently,the Cu/5CeO_(2)/ZnO catalyst with maximal Cu–ZnO interfaces exhibited the highest H 2 production rate of 94.6 mmolH2/(gcat·h),which was 1.5 and 10.2 times higher than those of Cu/ZnO and Cu/CeO_(2),respectively.
基金Project supported by the National Key Basic Research Program of China(2021YFA1501103)the National Science Fund for Distinguished Young Scholars of China(22225110)+1 种基金the National Natural Science Foundation of China(22075166,22271177)the Taishan Scholar Project of Shandong Province of China,and the Young Scholars Program of Shandong University.
文摘Developing high-performance ammonia decomposition catalysts for preparing COx-free hydrogen shows great practical significance.Herein,CeO_(2) is used as a promoter to modulate the metal-support interaction to enhance the catalytic performance of Ru/Al_(2)O_(3) catalysts.A series of 1Ru/xCe-10AI(x=0.5,1,or 3)catalysts was prepared by a facile colloidal deposition method.We find that the optimized 1 Ru/1Ce-10Al catalyst exhibits excellent activity for the decomposition of ammonia with a very high hydrogen yield of7097 mmolH2/(gRu·min)at 450℃.It is confirmed that Ru species are highly dispersed on the support surface as stable small clusters(~1.3 nm).More importantly,due to the interaction between Ru species and partially reduced CeO_(2-x),the electron density of Ru species is increased,which is beneficial to the high activity of the 1 Ru/xCe-10Al catalysts.This work paves a way to construct high-efficiency ammonia decomposition catalysts modified by CeO_(2).
基金Project supported by the Guangdong Provincial Education Department Special Project of Key Research Areas(2020ZDZX2066)the Innovation Team of Universities of Guangdong Province(2020KCXTD011)+2 种基金the Engineering Research Center of Universities of Guangdong Province(2019GCZX002)the Guangdong Key Laboratory for Hydrogen Energy Technologies(2018B030322005)Guangdong Basic and Applied Basic Research Foundation(2019A1515110586,2019A1515110534)。
文摘CeO_(2)/g-C_(3)N_(4)photocatalysts have attracted tremendous attention in the photocatalytic degradation of organic pollutants.The design and construction of highly active CeO_(2)/g-C_(3)N_(4)photocatalysts without harsh conditions are still challenging.Herein,highly dispersed CeO_(2-x)nanoparticles with rich oxygen vacancies were successfully precipitated on the surface of g-C_(3)N_(4)under mild conditions.The fabricated CeO_(2-x)/g-C_(3)N_(4)exhibits remarkable activity and stability for photocatalytic degradation of MO pollutant.The optimal rate constant of MO degradation over CeO_(2-x)/g-C_(3)N_(4)is about 0.031 min^(-1),which is three times higher than that of g-C_(3)N_(4).A negligible activity decrease is observed after three cycling runs.The enhanced catalytic performance can be ascribed to the excellent dispersion of CeO_(2-x)with rich oxygen vacancies that benefit O_(2)adsorption and visible light absorption.In addition,the proper band alignment between CeO_(2-x)and gC_(3)N_(4)is conducive to the highly efficient separation of photogenerated electron-hole pairs.
基金the National Natural Science Foundation of China(Nos.21103024,61171008)Natural Science Foundation of Zhejiang Province(No.LY19B060006)+1 种基金National Key Research and Development Program of China(No.2018YFB1502900)Technology Development Project of Jiaxing University(No.70518047)。
文摘Graphitic carbon nitride(g-C_(3)N_(4))-based materials are regarded as one of the most potential photocatalysts for utilizing solar energy.In this work,we reported a facile one step in-situ hydrothermal-roasting method for preparing honeycomb-like g-C_(3)N_(4)/CeO_(2) nanosheets with abundant oxygen vacancies(g-C_(3)N_(4)/CeO_(2)-x).The hydrothermal-roasting and incomplete-sealed state can(i)generate an in-situ reducing atmosphere(CO,N2,NH3) to tune the concentration of oxygen vacancies in CeO_(2);(ii) beneficial to prevent continuous growth of g-C_(3)N_(4) and results in honeycomb-like g-C_(3)N_(4)/CeO_(2)-x hybrid nanosheets.What is more,the g-C_(3)N_(4)/CeO_(2)-x photocatalyst exhibited extended photoresponse range,increased specific surface area and obviously enhanced separation efficiency of photogenerated electron-hole pairs.As a proof-of-concept application,the optimized g-C_(3)N_(4)/CeO_(2)-xnanosheets could achieve 98% removal efficiency for Cr(Ⅵ) under visible light irradiation(λ≥420 nm)within 2.5 h,which is significantly better than those of pure g-C_(3)N_(4) and CeO_(2).This work provides a new idea for more rationally designing and constructing g-C_(3)N_(4)-based catalysts for efficient extended photochemical application.
基金the National Key R&D Program of China (2021YFA1501302)the National Natural Science Foundation of China (22121004,U1862207)+1 种基金the Haihe Laboratory of Sustainable Chemical Transformations and the Program of Introducing Talents of Discipline to Universities (BP0618007) for financial supportsupported by the XPLORER PRIZE
文摘Rational design and performance promotion are eternal topics and ultimate goals in catalyst preparation.In contrast,trial–and–error is still the common method people take.Therefore,it is important to develop methods to intrinsically enhance the performance of catalysts.The most effective solutions are the one from a kinetic perspective based on clear knowledge of the reaction mechanism.This paper describes rate-determining step cognition and modulation to promote CO oxidation on highly dispersed Pt on CeO_(2).The different degrees of metal–support interactions due to variation of hydroxyl density of support could alter the structure of active species and the ability of oxygen activation apparently,further shift the rate-determining step from oxygen activation to oxygen reverse spillover kinetically.The transformation of rate-determining step could enhance the intrinsic activity significantly,and decrease the T_(50) approximately 140℃.The findings of this research exemplify the universal and effective method of performance elevation by rate-determining step modulation,which is promising for application in different systems.
