Cheng Yuanzhe, Xue Jing, Yang Min, Li Hongliang, Guo Peizhi
Institute of Materials for Energy and Environment, State Key Laboratory of Bio-fibers and Eco-textiles, College of Materials Science and Engineering, Qingdao University, Qingdao, 266071, P. R. China.
Inorg Chem. 2020 Aug 3;59(15):10611-10619. doi: 10.1021/acs.inorgchem.0c01056. Epub 2020 Jul 17.
Crystal phase structure of bimetallic alloy is an important factor determining the electrocatalytic activity toward oxidation of energy molecules. In this paper, PdCu bimetallic NPs with similar element composition and different crystal phase structural features have been synthesized hydrothermally by adjusting the content of ethylenediaminetetraacetic acid disodium salt (EDTA-2Na). Multiphase PdCu NPs composed of pure Pd and alloy phase are obtained with a low concentration (even as low as zero) of EDTA-2Na in synthetic systems while homogeneous PdCu alloy NPs are formed in the presence of EDTA-2Na with a high concentration. The catalytic activity of ethanol electrooxidation is increased from 3.1 mA·cm of pure Pd NPs, to 3.6 mA·cm of multiphase PdCu NPs, and to 5.0 mA·cm of homogeneous PdCu alloy NPs (about 2360 mA mg). The surface composition and structural stability of homogeneous PdCu NPs were much less damaged during electrochemical measurements. Based on the experimental data, the formation mechanism of multiphase and homogeneous PdCu NPs and their structure-property relationship have been discussed.
双金属合金的晶相结构是决定对能量分子氧化的电催化活性的重要因素。本文通过调节乙二胺四乙酸二钠盐（EDTA-2Na）的含量，水热合成了具有相似元素组成和不同晶相结构特征的PdCu双金属纳米粒子。在合成体系中，当EDTA-2Na浓度较低（甚至低至零）时，可得到由纯Pd和合金相组成的多相PdCu纳米粒子；而在高浓度EDTA-2Na存在下，则形成均匀的PdCu合金纳米粒子。乙醇电氧化的催化活性从纯Pd纳米粒子的3.1 mA·cm²提高到多相PdCu纳米粒子的3.6 mA·cm²，再提高到均匀PdCu合金纳米粒子的5.0 mA·cm²（约2360 mA mg）。在电化学测量过程中，均匀PdCu纳米粒子的表面组成和结构稳定性受损程度要小得多。基于实验数据，讨论了多相和均匀PdCu纳米粒子的形成机理及其结构-性能关系。
