Structural and chemical transformations of CuZn alloy nanoparticles under reactive redox atmospheres:An in situ TEM study  

作　　者：Shengnan Yue Qian Li Chaobin Zeng Alexander Klyushin Ramzi Farra Marc-Georg Willinger Xing Huang 

机构地区：[1]College of Chemistry,Fuzhou University,Fuzhou 350108,China [2]Qingyuan Innovation Laboratory,Quanzhou 362801,China [3]Hitachi High-Tech Scientific Solutions(Beijing)Co.,Ltd.,Beijing 100015,China [4]MAX IV Laboratory,Lund University,Box 118,22100 Lund,Sweden [5]Department of Inorganic Chemistry,Fritz-Haber Institute of Max Planck Society,Berlin 14195,Germany [6]Department of Chemistry,Technical University of Munich,Garching 85748,Germany

出　　处：《Nano Research》2024年第7期6265-6273,共9页纳米研究（英文版）

基　　金：supported by the Swedish Research council under contract 2018-07152;the Swedish Governmental Agency for Innovation Systems under contract 2018-04969;Formas under contract 2019-02496;X.H.thanks 1000 talent youth project,Fuzhou University and Qingyuan Innovation Laboratory for the financial support.

摘　　要：Alloying metals to form intermetallics has been proven effective in tuning the chemical properties of metal-based catalysts.However,intermetallic alloys can undergo structural and chemical transformations under reactive conditions,leading to changes in their catalytic function.Elucidating and understanding these transformations are crucial for establishing relevant structureperformance relationships and for the rational design of alloy-based catalysts.In this work,we used CuZn alloy nanoparticles(NPs)as a model material system and employed in situ transmission electron microscopy(TEM)to investigate the structural and chemical changes of CuZn NPs under H_(2),O_(2)and their mixture.Our results show how CuZn NPs undergo sequential transformations in the gas mixture at elevated temperatures,starting with gradual leaching and segregation of Zn,followed by oxidation at the NP surface.The remaining copper at the core of particles can then engage in dynamic behavior,eventually freeing itself from the zinc oxide shell.The structural dynamics arises from an oscillatory phase transition between Cu and Cu_(2)O and is correlated with the catalytic water formation,as confirmed by in situ mass spectrometry(MS).Under pure H_(2)or O_(2)atmosphere,we observe different structural evolution pathways and final chemical states of CuZn NPs compared to those in the gas mixture.These results clearly demonstrate that the chemical state of alloy NPs can vary considerably under reactive redox atmospheres,particularly for those containing elements with distinct redox properties,necessitating the use of in situ or detailed ex situ characterizations to gain relevant insights into the states of intermetallic alloy-based catalysts and structure-activity relationships.

关 键 词：In situ transmission electron microscopy(TEM) CuZn alloy structural and chemical transformations redox atmosphere 

分 类 号：TB383[一般工业技术—材料科学与工程]