Single-Site Metal-Organic Framework and Copper Foil Tandem Catalyst for Highly Selective CO 2 Electroreduction to C 2 H 4 .

Tandem catalysis is a promising way to break the limitation of linear scaling relationship for enhancing efficiency, and the desired tandem catalysts for electrochemical CO 2 reduction reaction (CO 2 RR) are urgent to be developed. Here, a tandem electrocatalyst created by combining Cu foil (CF) with a single-site Cu(II) metal-organic framework (MOF), named as Cu-MOF-CF, to realize improved electrochemical CO 2 RR performance, is reported. The Cu-MOF-CF shows suppression of CH 4 , great increase in C 2 H 4 selectivity (48.6%), and partial current density of C 2 H 4 at -1.11 V versus reversible hydrogen electrode. The outstanding performance of Cu-MOF-CF for CO 2 RR results from the improved microenvironment of the Cu active sites that inhibits CH 4 production, more CO intermediate produced by single-site Cu-MOF in situ for CF, and the enlarged active surface area by porous Cu-MOF. This work provides a strategy to combine MOFs with copper-based electrocatalysts to establish high-efficiency electrocatalytic CO 2 RR.