PdCu alloy nanoparticles supported on CeO2 nanorods: Enhanced electrocatalytic activity by synergy of compressive strain, PdO and oxygen vacancy
PdCu alloy nanoparticles supported on CeO2 nanorods: Enhanced electrocatalytic activity by synergy of compressive strain, PdO and oxygen vacancy
复制标题
CeO2纳米棒负载的PdCu合金纳米颗粒：通过压缩应变、PdO和氧空位的协同作用增强电催化活性
DOI：
10.1016/j.jcat.2019.04.027
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发表时间：
2019-06-01
影响因子：
7.3
通讯作者：
Chen, Shaowei
中科院分区：
文献类型：
--
作者：
Guo, Zhiwei;Kang, Xiongwu;Chen, Shaowei
金属氧化物通过金属-载体之间的强相互作用来促进金属催化剂的催化性能，已被广泛研究。然而，其背后的机制仍在争论中。本文制备了一系列尺寸为4.9~15.4 nm的PdCu纳米粒子，并将其负载到CeO2纳米棒上，用高分辨电子显微镜、X射线衍射仪、X射线光电子能谱和电化学CO溶出法对其进行了表征。PdCu纳米颗粒与CeO2纳米棒的耦合作用使PdCu纳米颗粒产生压应变，并强烈依赖于PdCu纳米颗粒的尺寸。进一步讨论了PdCu纳米粒子的压缩应变、d带中心下移、CO结合能降低和PdO含量增加之间的关系。综合分析认为，CeO2载体上PdCu纳米粒子上CO氧化电位的降低来自于PdCu上PdO的增强，而压缩应变、增强的PdO和氧空位的协同作用显著地促进了PdCu对甲酸电氧化的催化性能。(C)2019 Elsevier Inc.保留所有权利。
Metal oxides have been widely studied as promoter of catalytic performance of metal catalysts through the strong metal-support interactions. However, the mechanism behind it is still debating. Here a series of PdCu nanoparticles with size from 4.9 to 15.4 nm are prepared and loaded on CeO2 nanorods, which are further characterized by HRTEM, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and electrochemical CO stripping. The coupling of PdCu nanoparticles and CeO2 nanorods induces compressive strain on PdCu nanoparticles, which is strongly dependent on the size of PdCu nanoparticles. The correlation among the compressive strain, down-shift of the d-band center, reduced CO binding energy and augmentation of PdO content for PdCu nanoparticles is further discussed in details. Based on comprehensive analyses, it is concluded that the reduced CO oxidation potential on PdCu nanoparticles upon CeO2 support is from enhanced PdO on PdCu, while the synergy of compressive strain, enhanced PdO and oxygen vacancy remarkably promotes the catalytic performance of PdCu towards electrooxidation of formic acid. (C) 2019 Elsevier Inc. All rights reserved.