Microwave-induced surface amorphization of Cu2(OH)2CO3 catalyst promotes multi-carbon products selectivity of CO2 electroreduction

Abstract

For CO₂ electroreduction, efficient catalysts with superior selectivity toward multi-carbon (C₂₊) products (such as C₂H₄, C₂H₅OH, etc.) are intensely desired. Amorphous Cu-based catalysts show appealing performance on the crucial C–C coupling, but their synthesis procedures are complicated and their actual mechanisms are still unclear. In this work, surface amorphization has been implemented on Cu₂(OH)₂CO₃ catalysts by a very simple microwave-induction method, improving the Faradaic efficiency for C₂₊ products (\({\rm FE}_{{\rm C}_{2+}}\)) up to 86% (increased by ∼26% than that on Cu₂(OH)₂CO₃) at a partial current density of 258 mA cm⁻², and a high \({\rm FE}_{{\rm C}_{2+}}\) of 75% at 500 mA cm⁻² in a flow cell. Moreover, the catalyst exhibits good stability. In situ investigations disclose that the amorphous surface optimizes the adsorption state (binding mode and coverage) of key intermediate *CO and stabilizes Cu⁺ pieces, facilitating the dimerization of *CO into *OCCO and hydrogenation to *OC₂H₅, ultimately achieving high yields of C₂₊ products. This work highlights a simple microwave approach for surface amorphization and the roles of amorphous features in CO₂ reduction to C₂₊ products, which could be valuable references for designing high-performance catalysts for CO₂ electroreduction.