Engineering Crystalline/Amorphous Interfaces for Enhanced CO2 Electroreduction.

In the request for carbon neutrality, CO2 electroreduction to high-value fuels and chemicals, particularly formic acid, has become as a promising approach. However, implementing it on an industrial scale is hindered by the catalyst instability under high current densities and the excessive energy consumption of conventional electrolysis systems. To tackle these challenges, we propose an amorphization strategy to regulate catalyst reconstruction under operational conditions. In particular, an amorphous In-based catalyst, InOx(OH)3-2x, was designed and achieved high Faradaic efficiencies of 98% at -800 to -1000 mA cm-2 for CO2 electroreduction to formate, while maintaining stability for 100 hours. Mechanistic studies show that InOx(OH)3-2x undergoes partial reduction to stable crystalline/amorphous In/In-OH interfaces instead of fully reducing to metallic In, enhancing the adsorption of CO2 and *OCHO intermediate. To improve the economic viability of electrolysis system, a CO2 electroreduction coupled with waste plastics electrooxidation system for formate production was constructed. Compared to conventional electrolysis system, the coupled system reduced energy consumption by 34.7% and increased formate production by 49.7%, offering a more energy-efficient and cost-effective approach to CO2 electroreduction.