Ru@Pt Core-Shell Nanoparticles: Impact of the Atomic Ordering of the Ru Metal Core on the Electrocatalytic Activity of the Pt Shell
Ru@Pt Core-Shell Nanoparticles: Impact of the Atomic Ordering of the Ru Metal Core on the Electrocatalytic Activity of the Pt Shell
复制标题
Ru@Pt 核壳纳米颗粒：Ru 金属核的原子有序性对 Pt 壳电催化活性的影响
DOI：
10.1021/acssuschemeng.9b01270
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发表时间：
2019
影响因子：
8.4
通讯作者：
Chen Shaowei
中科院分区：
文献类型：
--
作者：
Zou Jiasui;Wu Min;Ning Shunlian;Huang Lin;Kang Xiongwu;Chen Shaowei
构建核壳结构是提高金属纳米粒子催化活性的有效途径。然而，金属核的原子有序性对壳的性能的影响仍然未被探索。在这里，钌铂（Ru-Pt）核壳纳米粒子，具有相同直径的结晶和非晶Ru核和不同的Pt壳厚度，制备和表征的X射线衍射（XRD），X射线光电子能谱（XPS），高角度环形暗场扫描跃迁电子能谱（HAADF-STEM），和CO跳闸伏安法。观察到了良好定义的异质结构Ru-Pt界面和Pt壳在晶态Ru核（Ru@Ptx）上的各向异性生长，而非晶态Ru核诱导Ru-Pt界面处的部分合金和Pt壳的各向同性生长。核-壳结构也导致Pt的d-带中心明显下移，其在非晶Ru核上比在结晶Ru核上消散得快得多，如XRD和CO解吸电位所示。两组核-壳纳米粒子的催化活性的火山形状依赖于Pt壳和结晶Ru核的厚度显着提高对甲酸和乙醇的电氧化的催化性能和稳定性，这归因于Pt壳的晶格应变，d-带中心的下移，减弱CO吸附，从而减轻中毒。
Constructing core–shell nanostructures is demonstrated to be an effective strategy to improve catalytic activity of metal nanoparticles. However, the impact of the atomic ordering of the metal core on the performance of the shell remains unexplored. Here, ruthenium–platinum (Ru–Pt) core–shell nanoparticles, with a crystalline and amorphous Ru core of the same diameter and diverse Pt shell thicknesses, are prepared and characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), high-angle annular dark-field scanning transition electron spectroscopy (HAADF-STEM), and CO tripping voltammetry. The well-defined heterostructured Ru–Pt interface and anisotropic growth of the Pt shell on the crystalline Ru core (Ru@Ptx) were observed, while the amorphous Ru core induces a partial alloy at the Ru–Pt interface and isotropic growth of the Pt shell. The core–shell structure also results in an apparent down-shift of the d-band center of Pt, which dissipates much faster on the amorphous Ru core than on crystalline ones, as demonstrated by the XRD and CO desorption potential. The two sets of core–shell nanoparticles show that a volcano-shape dependence of the catalytic activity on the thickness of the Pt shell and the crystalline Ru core markedly enhanced the catalytic performance and stability toward electro-oxidation of formic acid and ethanol, which is ascribed to the lattice strain of the Pt shell, down-shift of the d-band center, the weakened CO adsorption, and thus alleviated poisoning.