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
贾鹤林 1郭兴 2张新亮 3周柱坤 2魏伟 2许征兵 1陶小马4
作者信息
- 1. 广西大学资源环境与材料学院,广西南宁 530004;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
- 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;广西大学机械工程学院,广西南宁 530004
- 3. 广西大学机械工程学院,广西南宁 530004
- 4. 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;广西大学物理科学与工程技术学院,广西南宁 530004
- 折叠
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)Tm时,两者呈线性相关,Rsn=T/Tm+1.1;在温度为(0.8～1.0)Tm时,烧结颈随温度的增加迅速长大,两者关系近似为Rsn=35(T/Tm)2-52.5 T/Tm)+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.
Abstract
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)Tm(melting temperature),the relationship is linear,Rsn=T/Tm+1.1;while within the range of(＞0.8～1.0)Tm,the growth of sintering necks rapidly accelerates with increasing temperature,showing an approximate exponential relationship,Rsn=35(T/Tm)2-52.5(T/Tm)+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Key words
catalysis/sintering/copper-palladium alloy/nanoparticles/molecular dynamics simulation引用本文复制引用
基金项目
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)
出版年
2024
NETL
NSTL
万方数据