The catalytic activity of noble-metal nanocrystals is mainly determined by their sizes and the facets exposed on the surface. For single crystals, it has been demonstrated that the Pd（100） surface is catalytically m...The catalytic activity of noble-metal nanocrystals is mainly determined by their sizes and the facets exposed on the surface. For single crystals, it has been demonstrated that the Pd（100） surface is catalytically more active than both Pd（110） and Pd（111） surfaces for the CO oxidation reaction. Here we report the synthesis of Pd nanocrystals enclosed by {100} facets with controllable sizes in the range of 6-18 nm by manipulating the rate of reduction of the precursor. UV-vis spectroscopy studies indicate that the rate of reduction of Na2PdC14 can be controlled by adjusting the concentrations of Br- and C1- ions added to the reaction mixture. Pd nanocrystals with different sizes were immobilized on ZnO nanowires and evaluated as catalysts for CO oxidation. We found that the activity of this catalytic system for CO oxidation showed a strong dependence on the nanocrystal size. When the size of the Pd nanocrystals was reduced from 18 nm to 6 nm, the maximum conversion rate was significantly enhanced by a factor of -10 and the corresponding maximum conversion temperature was lowered by -80℃.展开更多
Metal nanocrystals have been recognized as the main catalytic materials in many fields,but insufficient activity and stability,as well as high prices,have limited their large-scale potential applications.As one of the...Metal nanocrystals have been recognized as the main catalytic materials in many fields,but insufficient activity and stability,as well as high prices,have limited their large-scale potential applications.As one of the extremely promising alternatives toward metal in boosting their catalytic performance,nonmetallic atoms-doped metal nanocrystals have recently received extensive attention because of their high efficiency,chemical and structural durability,abundant reserve,and low cost.In this review,we highlight the most recent progress in this field and provide insights into their catalytic applications.The metalnonmetal nanocrystals prepared by doping metal nanocrystals with nonmetallic atoms are introduced and classified based on the types of nonmetallic atoms,including metal hydrides,borides,carbides,nitrides,oxides,phosphides,and chalcogenides.Besides,their applications in catalysis,especially in electrocatalysis and organic catalysis,have been summarized and discussed.Finally,the conclusions and perspectives are given for the catalysis-driven rational design of metal-nonmetal nanocrystals in this minireview.展开更多
文摘The catalytic activity of noble-metal nanocrystals is mainly determined by their sizes and the facets exposed on the surface. For single crystals, it has been demonstrated that the Pd（100） surface is catalytically more active than both Pd（110） and Pd（111） surfaces for the CO oxidation reaction. Here we report the synthesis of Pd nanocrystals enclosed by {100} facets with controllable sizes in the range of 6-18 nm by manipulating the rate of reduction of the precursor. UV-vis spectroscopy studies indicate that the rate of reduction of Na2PdC14 can be controlled by adjusting the concentrations of Br- and C1- ions added to the reaction mixture. Pd nanocrystals with different sizes were immobilized on ZnO nanowires and evaluated as catalysts for CO oxidation. We found that the activity of this catalytic system for CO oxidation showed a strong dependence on the nanocrystal size. When the size of the Pd nanocrystals was reduced from 18 nm to 6 nm, the maximum conversion rate was significantly enhanced by a factor of -10 and the corresponding maximum conversion temperature was lowered by -80℃.
基金the support of the National Natural Science Foundation of China(NSFC,Nos.21773180 and 21471123)State Key Laboratory for Mechanical Behavior of Materials+2 种基金“the Fundamental Research Funds for the Central Universities”“the World-Class Universities(Disciplines)the Characteristic Development Guidance Funds for the Central Universities”by Xi’an Jiaotong University。
文摘Metal nanocrystals have been recognized as the main catalytic materials in many fields,but insufficient activity and stability,as well as high prices,have limited their large-scale potential applications.As one of the extremely promising alternatives toward metal in boosting their catalytic performance,nonmetallic atoms-doped metal nanocrystals have recently received extensive attention because of their high efficiency,chemical and structural durability,abundant reserve,and low cost.In this review,we highlight the most recent progress in this field and provide insights into their catalytic applications.The metalnonmetal nanocrystals prepared by doping metal nanocrystals with nonmetallic atoms are introduced and classified based on the types of nonmetallic atoms,including metal hydrides,borides,carbides,nitrides,oxides,phosphides,and chalcogenides.Besides,their applications in catalysis,especially in electrocatalysis and organic catalysis,have been summarized and discussed.Finally,the conclusions and perspectives are given for the catalysis-driven rational design of metal-nonmetal nanocrystals in this minireview.
