Simultaneous Defect and Size Control of Metal–Organic Framework Nanostructures for Highly Efficient Carbon Dioxide Electroreduction to Multicarbon Products

Electrocatalytic carbon dioxide (CO2) reduction reaction (CO2RR) has offered a sustainable approach in converting an anthropogenic CO2 source to chemicals and fuels to promote carbon neutral. However, it remains challenging to prepare high-performance catalysts for efficient and selective CO2 electroreduction, especially toward the high-vaule multicarbon products. Here we report the facile synthesis of four kinds of nearly monodispersed CuTrz (HTrz = 1H,1,2,4-triazole) metal–organic framework (MOF) nanostructures with different sizes by controlling the reaction kinetics. Significantly, small CuTrz nanostructures demonstrate much superior CO2RR performance over the large counterparts toward multicarbon production in neutral electrolytes, with optimized Faradaic efficiency of 55.4% and 81.8% for ethylene and multicarbon products, respectively. Detailed structural characterizations reveal that small CuTrz nanostructures are polycrystalline and rich in grain boundaries, while the large ones are single crystalline. This work highlights the importance of simultaneous defect and size control of MOFs in boosting their CO2RR performance for multicarbon production.