研究人员发现，负载于γ-Al2 O3之上的孤立钯原子和少量氧化镧一起，在较低温度（40℃）下即可将汽车尾气中的 CO 转化成 CO2，提供了一条降低汽车尾气有毒物质排放的新途径，对改善汽车启动时排放效果更明显，并且汽车催化转化器上的...研究人员发现，负载于γ-Al2 O3之上的孤立钯原子和少量氧化镧一起，在较低温度（40℃）下即可将汽车尾气中的 CO 转化成 CO2，提供了一条降低汽车尾气有毒物质排放的新途径，对改善汽车启动时排放效果更明显，并且汽车催化转化器上的铂会被替代或者需求减少。展开更多
Cu‐alloyed Pd single‐atom catalysts exhibit excellent catalytic performance for the semi‐hydrogenation of acetylene;however,the limit of the Cu/Pd atomic ratio for forming the alloyed Pd single‐atom catalyst is am...Cu‐alloyed Pd single‐atom catalysts exhibit excellent catalytic performance for the semi‐hydrogenation of acetylene;however,the limit of the Cu/Pd atomic ratio for forming the alloyed Pd single‐atom catalyst is ambiguous.Herein,silica‐supported Cu-Pd bimetallic catalysts with fixed Pd content and varied Cu loadings were synthesized using an incipient wetness co‐impregnation method.The X‐ray absorption spectroscopy results indicated that Pd formed an alloy with Cu after reduction at250°C and that the Pd atoms were completely isolated by Cu for Cu/Pd atomic ratios≥40/1.Notably,increasing the reduction temperature from250to400°C hardly affected the catalytic performances of the Cu-Pd/SiO2catalysts.This finding can be attributed to the similar chemical environments of Pd demonstrated by the X‐ray absorption spectroscopy results.展开更多
Palladium(Pd)‐based catalysts are essential to drive high‐performance Suzuki coupling reactions,which are powerful tools for the synthesis of functional organic compounds.Herein,we developed a solution‐rapid‐annea...Palladium(Pd)‐based catalysts are essential to drive high‐performance Suzuki coupling reactions,which are powerful tools for the synthesis of functional organic compounds.Herein,we developed a solution‐rapid‐annealing process to stabilize nitrogen‐mesoporous carbon supported Pd single‐atom/cluster(Pd/NMC)material,which provided a catalyst with superior performance for Suzuki coupling reactions.In comparison with commercial palladium/carbon(Pd/C)catalysts,the Pd/NMC catalyst exhibited significantly boosted activity(100%selectivity and 95%yield)and excellent stability(almost no decay in activity after 10 reuse cycles)for the Suzuki coupling reactions of chlorobenzenes,together with superior yield and excellent selectivity in the fields of the board scope of the reactants.Moreover,our newly developed rapid annealing process of precursor solutions is applied as a generalized method to stabilize metal clusters(e.g.Pd,Pt,Ru),opening new possibilities in the construction of efficient highly dispersed metal atom and sub‐nanometer cluster catalysts with high performance.展开更多
Nanoclusters with a precise number of atoms may exhibit unique and often unexpected catalytic properties.Here,we report an atomically precise Pd3 nanocluster as an efficient catalyst,whose catalytic performance differ...Nanoclusters with a precise number of atoms may exhibit unique and often unexpected catalytic properties.Here,we report an atomically precise Pd3 nanocluster as an efficient catalyst,whose catalytic performance differs remarkably from typical Pd nanoparticle catalysts,with excellent reactivity and selectivity in the one-pot synthesis of benzalaniline from nitrobenzene and benzaldehyde.We anticipate that our work will serve as a starting point for the catalytic applications of these tiny atomically precise nanoclusters in green chemistry for the one-pot syntheses of fine chemicals.展开更多
An account of recent work on supported single‐atom catalyst design is given here for reactions as diverse as the low‐temperature water‐gas shift,methanol steam reforming,selective ethanol dehydrogenation,and select...An account of recent work on supported single‐atom catalyst design is given here for reactions as diverse as the low‐temperature water‐gas shift,methanol steam reforming,selective ethanol dehydrogenation,and selective hydrogenation of alkynes and dienes.It is of fundamental interest to investigate the intrinsic activity and selectivity of the active metal atom site and compare them to the properties of the corresponding metal nanoparticles and sub‐nm clusters.It is also important to understand what constitutes a stable active metal atom site in the various reaction environments,and maximize their loadings to allow us to design robust catalysts for industrial applications.Combined activity and stability studies,ideally following the evolution of the active site as a function of catalyst treatment in real time are recommended.Advanced characterization methods with atomic resolution will play a key role here and will be used to guide the design of new catalysts.展开更多
基金supported by the National Natural Science Foundation of China(21303194,21476227,21522608 and 21690084)Youth Innovation Promotion Association of the Chinese Academy of Sciences(2014163)+2 种基金the National Key Projects for Fundamental Research and Development of China(2016YFA0202801)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB17020100)the department of science and technology of Liaoning province under contract of 2015020086-101~~
文摘Cu‐alloyed Pd single‐atom catalysts exhibit excellent catalytic performance for the semi‐hydrogenation of acetylene;however,the limit of the Cu/Pd atomic ratio for forming the alloyed Pd single‐atom catalyst is ambiguous.Herein,silica‐supported Cu-Pd bimetallic catalysts with fixed Pd content and varied Cu loadings were synthesized using an incipient wetness co‐impregnation method.The X‐ray absorption spectroscopy results indicated that Pd formed an alloy with Cu after reduction at250°C and that the Pd atoms were completely isolated by Cu for Cu/Pd atomic ratios≥40/1.Notably,increasing the reduction temperature from250to400°C hardly affected the catalytic performances of the Cu-Pd/SiO2catalysts.This finding can be attributed to the similar chemical environments of Pd demonstrated by the X‐ray absorption spectroscopy results.
文摘Palladium(Pd)‐based catalysts are essential to drive high‐performance Suzuki coupling reactions,which are powerful tools for the synthesis of functional organic compounds.Herein,we developed a solution‐rapid‐annealing process to stabilize nitrogen‐mesoporous carbon supported Pd single‐atom/cluster(Pd/NMC)material,which provided a catalyst with superior performance for Suzuki coupling reactions.In comparison with commercial palladium/carbon(Pd/C)catalysts,the Pd/NMC catalyst exhibited significantly boosted activity(100%selectivity and 95%yield)and excellent stability(almost no decay in activity after 10 reuse cycles)for the Suzuki coupling reactions of chlorobenzenes,together with superior yield and excellent selectivity in the fields of the board scope of the reactants.Moreover,our newly developed rapid annealing process of precursor solutions is applied as a generalized method to stabilize metal clusters(e.g.Pd,Pt,Ru),opening new possibilities in the construction of efficient highly dispersed metal atom and sub‐nanometer cluster catalysts with high performance.
基金financial supports from National Natural Science Foundation of China(21773109,91845104)~~
文摘Nanoclusters with a precise number of atoms may exhibit unique and often unexpected catalytic properties.Here,we report an atomically precise Pd3 nanocluster as an efficient catalyst,whose catalytic performance differs remarkably from typical Pd nanoparticle catalysts,with excellent reactivity and selectivity in the one-pot synthesis of benzalaniline from nitrobenzene and benzaldehyde.We anticipate that our work will serve as a starting point for the catalytic applications of these tiny atomically precise nanoclusters in green chemistry for the one-pot syntheses of fine chemicals.
基金financial support of the work by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES), under Awards Grant Number DE-FG02-05ER15730
文摘An account of recent work on supported single‐atom catalyst design is given here for reactions as diverse as the low‐temperature water‐gas shift,methanol steam reforming,selective ethanol dehydrogenation,and selective hydrogenation of alkynes and dienes.It is of fundamental interest to investigate the intrinsic activity and selectivity of the active metal atom site and compare them to the properties of the corresponding metal nanoparticles and sub‐nm clusters.It is also important to understand what constitutes a stable active metal atom site in the various reaction environments,and maximize their loadings to allow us to design robust catalysts for industrial applications.Combined activity and stability studies,ideally following the evolution of the active site as a function of catalyst treatment in real time are recommended.Advanced characterization methods with atomic resolution will play a key role here and will be used to guide the design of new catalysts.
