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Tailoring lattice strain in ultra-fine high-entropy alloys for active and stable methanol oxidation

2021; Springer Science+Business Media; Volume: 64; Issue: 10 Linguagem: Inglês

10.1007/s40843-020-1635-9

2199-4501

Dongdong Wang, Zhiwen Chen, Yucheng Huang, Wei Li, Juan Wang, Zhuole Lu, Kaizhi Gu, Tehua Wang, Yujie Wu, Chen Chen, Yiqiong Zhang, Xiaoqing Huang, Tao Li, Chung‐Li Dong, Jun Chen, Chandra Veer Singh, Shuangyin Wang,

High-Temperature Coating Behaviors

High-entropy alloys (HEAs) have been widely studied due to their unconventional compositions and unique physicochemical properties for various applications. Herein, for the first time, we propose a surface strain strategy to tune the electrocatalytic activity of HEAs for methanol oxidation reaction (MOR). High-resolution aberration-corrected scanning transmission electron microscopy (STEM) and elemental mapping demonstrate both uniform atomic dispersion and the formation of a face-centered cubic (FCC) crystalline structure in PtFeCoNiCu HEAs. The HEAs obtained by heat treatment at 700°C (HEA-700) exhibit 0.94% compressive strain compared with that obtained at 400°C (HEA-400). As expected, the specific activity and mass activity of HEA-700 is higher than that of HEA-400 and most of the state-of-the-art catalysts. The enhanced MOR activity can be attributed to a shorter Pt-Pt bond distance in HEA-700 resulting from compressive strain. The nonprecious metal atoms in the core could generate compressive strain and down shift d-band centers via electron transfer to surface Pt layer. This work presents a new perspective for the design of high-performance HEAs electrocatalysts.