Designing highly efficient oxygen evolution reaction electrocatalyst of high-entropy oxides FeCoNiZrOx: Theory and experiment

Abstract

The correlations between the experimental methods and catalytic activities are urgent to be defined for the design of highly efficient catalysts. In this work, a new oxygen evolution reaction electrocatalyst of high-entropy oxide (HEO) FeCoNiZrOx was designed and analyzed by experimental and theoretical methods. On account of the shortened coordinate bond along with the increased annealing temperature, the atomic/electronic structures of active site were adjusted quantitatively with the aid of the pre-designed correlator of d electron density, which contributed to adjust the catalytic activity of HEO specimens. The prepared HEO specimen exhibited the low overpotentials of 245mV at 10 mA cm-2 and 288mV at 100 mA cm-2 with small Tafel slope of 35.66mV dec-1, fast charge transfer rate, and stable electrocatalytic activity. This strategy would be adopted to improve the catalytic activity of HEO by adjusting the d electron density of transition metal ions with suitable preparation method.