Industrial-level CO2 to formate conversion on Turing-structured electrocatalysts

Abstract

Industrializing the electrosynthesis of formate from CO2 reduction in membrane electrode assembly (MEA) electrolysers necessitates tuning both electrocatalysts and the interfacial water microenvironment. Here we cast a series of Turing-structured topology electrocatalysts, which can control the reorientation of interfacial water through the tuning of surface oxophilicity, for industrial-level conversion of CO2 to formate. Experimental and theoretical results verify the precisely modulated reorientation of interfacial water, with the ratios of four-coordinated to two-coordinated hydrogen-bonded interfacial water ranging from 0.26 to 3.10 over Turing-structured topology catalysts. We further demonstrate the efficiency of these strategies in sustaining high-rate formate electrosynthesis across a wide range of industrial-level current densities (300–1,000 mA cm−2) and formulate a volcano relationship to describe the relation. The optimal Turing Sb0.1Sn0.9O2 catalyst achieves a formate Faradaic efficiency of 92.0% at 1,000 mA cm-2 and exhibits a stability of 200 h at 500 mA cm-2 in a membrane electrode assembly electrolyser. Our findings highlight the prospect of topology-mediated tunings of the interfacial water microenvironment for electrifying the conversion of CO2 to formate, with promising implications for the electrosynthesis of other valuable chemicals. Turing-structured topology electrocatalysts are reported to control the reorientation of interfacial water through the tuning of surface oxophilicity. The optimal Turing catalyst achieves a formate Faradaic efficiency of 92.0% at 1,000 mA cm−2.