表面原子扩散驱动的铜钯纳米颗粒烧结行为  

Sintering behavior of Cu-Pd nanoparticles driven by surface atomic diffusion

作　　者：贾鹤林 郭兴 张新亮 周柱坤 魏伟 许征兵 陶小马 JIA Helin;GUO Xing;ZHANG Xinliang;ZHOU Zhukun;WEI Wei;XU Zhengbing;TAO Xiaoma(School of Resource,Environment and Materials,Guangxi University,Nanning 530004,China;State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures,Nanning 530004,China;School of Mechanical Engineering,Guangxi University,Nanning 530004,China;School of Physical and Technology,Guangxi University,Nanning 530004,China)

机构地区：[1]广西大学资源环境与材料学院,广西南宁530004 [2]省部共建特色金属材料与组合结构全寿命安全国家重点实验室,广西南宁530004 [3]广西大学机械工程学院,广西南宁530004 [4]广西大学物理科学与工程技术学院,广西南宁530004

出　　处：《广西大学学报（自然科学版）》2024年第3期654-664,共11页Journal of Guangxi University（Natural Science Edition）

基　　金：国家重点研发计划项目(2021YFE0203500);广西重点研发计划项目(GKAD230626101);广西科技基地和人才专项(GKAD21238021)。

摘　　要：铜钯双金属纳米颗粒是一种新型纳米催化剂。该纳米颗粒的烧结过程显著影响其比表面积和表面成分,这对催化效率起着关键作用。为了深入理解铜钯双金属纳米颗粒的烧结机制,本研究基于分子动力学探究了直径为6 nm的铜钯异种金属纳米颗粒在不同温度下的等温烧结行为。结果表明,烧结颈的长大速度同温度相关。在温度为(0.5~0.8)T_(m)时,两者呈线性相关,R_(sn)=T/T_(m)+1.1;在温度为(0.8~1.0)T_(m)时,烧结颈随温度的增加迅速长大,两者关系近似为R_(sn)=35(T/T_(m))2-52.5 T/T_(m)+21.5。铜钯纳米颗粒初期的烧结行为主要由低熔点表面铜原子扩散所驱动。同时,较低的混合焓促进铜、钯原子结合的作用,提高钯原子的扩散能力,驱动着铜钯纳米颗粒烧结由表向里的持续进行。Bimetallic copper-palladium(Cu-Pd)nanoparticles are a novel type of nanocatalyst.The sintering process of these nanoparticles plays a crucial role in catalytic efficiency through changes in specific surface area and surface composition.To gain a deeper understanding of the sintering mechanism of Cu-Pd bimetallic nanoparticles,this study employed molecular dynamics simulations to investigate the isothermal sintering behavior of 6 nm diameter Cu-Pd heterostructured nanoparticles at various temperatures.The results indicate a correlation between the growth rate of sintering necks and temperature.within the range of(0.5~0.8)T_(m)(melting temperature),the relationship is linear,R_(sn)=T/T_(m)+1.1;while within the range of(>0.8~1.0)T_(m),the growth of sintering necks rapidly accelerates with increasing temperature,showing an approximate exponential relationship,R_(sn)=35(T/T_(m))2-52.5(T/T_(m))+21.5.The initial sintering behavior of Cu-Pd nanoparticles is primarily driven by the diffusion of low-melting-point copper surface atoms.Additionally,the relatively low mixing enthalpy facilitates the bonding between Cu and Pd atoms,enhancing the diffusion capability of Pd atoms,driving the continuous inward sintering of Cu-Pd nanoparticles.

关 键 词：催化 烧结 铜钯合金 纳米颗粒 分子动力学 

分 类 号：TF124[冶金工程—粉末冶金] O793[冶金工程—冶金物理化学]