CuMoRuFeW high entropy alloy surfaced nanorods: Superior electrochemical CO2 reduction to ethylene

Abstract

Electrocatalytic carbon dioxide reduction (CO₂ER) driven by renewable energy sources to produce high-value-added chemicals is a highly promising strategy for achieving a closed carbon cycle. Cu is the only highly active catalyst capable of producing multi-carbon (C₂₊) products through CO₂ER. However, due to the constraints of existing scaling relationships and competing hydrogen evolution reaction, it is still challenging to achieve high selectivity of a single desired product. In this work, high-entropy alloy (HEA) CuMoRuFeW surface skin on Cu nanorods was obtained by a one-pot co-reduction method. It is revealed that Fe could effectively facilitate the co-reduction of Mo and W precursors and the formation of HEA surface on Cu nanorod. The Faradaic efficiency (FE) for ethylene and ethanol in CO₂ER reaches 49.5% and 20.4%, respectively, with a total FE_C2 of 69.9% and current density of 250 mA cm⁻² at −1.1 V vs. RHE. Theoretical calculations reveal that the Cu–W–Fe combination site is more active in CO₂ activation and C–C coupling for C₂ products than other sites. This work underscores the importance of HEA in overcoming the constraints of linear scaling relationships and improving the selectivity for C₂ products in CO₂ER.