本文首先利用等体积共浸渍法合成了一系列Pd/Sn比(原子比)不同的Pd_(1)-Sn_(x)/Al_(2)O_(3)双金属催化剂,然后通过多相催化仲氢诱导极化(PHIP)技术研究了Pd-Sn/Al_(2)O_(3)双金属催化剂上1,3-丁二烯选择性加氢反应.结果发现催化剂的Pd/S...本文首先利用等体积共浸渍法合成了一系列Pd/Sn比(原子比)不同的Pd_(1)-Sn_(x)/Al_(2)O_(3)双金属催化剂,然后通过多相催化仲氢诱导极化(PHIP)技术研究了Pd-Sn/Al_(2)O_(3)双金属催化剂上1,3-丁二烯选择性加氢反应.结果发现催化剂的Pd/Sn比会影响1,3-丁二烯反应活性和丁烯选择性:随着Pd/Sn比的下降,反应中1,3-丁二烯转化率降低,丁烯选择性提高.利用PASADENA(parahydrogen and synthesis allow for dramatically enhanced nuclear alignment)技术,发现Pd/Sn比的变化影响了1-丁烯与2-丁烯之间的异构化过程:随着Pd/Sn比的下降,1-丁烯异构化率降低,这是由于Sn组分含量的提高减少了表面暴露的Pd组分,使得催化剂反应活性降低;Sn组分含量的提高同时导致了Pd电子密度的上升,使得选择性还原产物丁烯更易脱附,阻止其进一步加氢生成丁烷,并抑制了1-丁烯异构化反应过程.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
Selective hydrogenation of 1,3‐butadiene is an essential process in the upgrading of the crude C4 cut from the petroleum chemical sector.Catalyst design is crucial to achieve a virtually alkadiene‐free product while...Selective hydrogenation of 1,3‐butadiene is an essential process in the upgrading of the crude C4 cut from the petroleum chemical sector.Catalyst design is crucial to achieve a virtually alkadiene‐free product while avoiding over‐hydrogenating valuable olefins.In addition to the great industrial relevance,this demanding selectivity pattern renders 1,3‐butadiene hydrogenation a widely used model reaction to discriminate selective hydrogenation catalysts in academia.Nonetheless,critical reviews on the catalyst development are extremely lacking in literature.In this review,we aim to provide the reader an in‐depth overview of different catalyst families,particularly the precious metal‐based monometallic catalysts(Pd,Pt,and Au),developed in the last half century.The emphasis is placed on the development of new strategies to design high‐performance architectures,the establishment of structure‐performance relationships,and the reaction and deactivation mechanisms.Thrilling directions for future optimization of catalyst formulations and engineering aspect are also provided.展开更多
基金supported as part of the Catalysis Center for Energy Innovation, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Basic Energy Sciences under Award Number DE-SC0001004Program for New Century Excellent Talents in University of China (NCET-12-0297)~~
文摘本文首先利用等体积共浸渍法合成了一系列Pd/Sn比(原子比)不同的Pd_(1)-Sn_(x)/Al_(2)O_(3)双金属催化剂,然后通过多相催化仲氢诱导极化(PHIP)技术研究了Pd-Sn/Al_(2)O_(3)双金属催化剂上1,3-丁二烯选择性加氢反应.结果发现催化剂的Pd/Sn比会影响1,3-丁二烯反应活性和丁烯选择性:随着Pd/Sn比的下降,反应中1,3-丁二烯转化率降低,丁烯选择性提高.利用PASADENA(parahydrogen and synthesis allow for dramatically enhanced nuclear alignment)技术,发现Pd/Sn比的变化影响了1-丁烯与2-丁烯之间的异构化过程:随着Pd/Sn比的下降,1-丁烯异构化率降低,这是由于Sn组分含量的提高减少了表面暴露的Pd组分,使得催化剂反应活性降低;Sn组分含量的提高同时导致了Pd电子密度的上升,使得选择性还原产物丁烯更易脱附,阻止其进一步加氢生成丁烷,并抑制了1-丁烯异构化反应过程.
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.
基金supported by Zhejiang Normal University (YS304320035, YS304320036)
文摘Selective hydrogenation of 1,3‐butadiene is an essential process in the upgrading of the crude C4 cut from the petroleum chemical sector.Catalyst design is crucial to achieve a virtually alkadiene‐free product while avoiding over‐hydrogenating valuable olefins.In addition to the great industrial relevance,this demanding selectivity pattern renders 1,3‐butadiene hydrogenation a widely used model reaction to discriminate selective hydrogenation catalysts in academia.Nonetheless,critical reviews on the catalyst development are extremely lacking in literature.In this review,we aim to provide the reader an in‐depth overview of different catalyst families,particularly the precious metal‐based monometallic catalysts(Pd,Pt,and Au),developed in the last half century.The emphasis is placed on the development of new strategies to design high‐performance architectures,the establishment of structure‐performance relationships,and the reaction and deactivation mechanisms.Thrilling directions for future optimization of catalyst formulations and engineering aspect are also provided.