Coordination environment dependent selectivity of single-site-Cu enriched crystalline porous catalysts in CO(2) reduction to CH(4)

The electrochemical CO(2) reduction to high-value-added chemicals is one of the most promising and challenging research in the energy conversion field. An efficient ECR catalyst based on a Cu-based conductive metal-organic framework (Cu-DBC) is dedicated to producing CH(4) with superior activity and selectivity, showing a Faradaic efficiency of CH(4) as high as ~80% and a large current density of −203 mA cm(−2) at −0.9 V vs. RHE. The further investigation based on theoretical calculations and experimental results indicates the Cu-DBC with oxygen-coordinated Cu sites exhibits higher selectivity and activity over the other two crystalline ECR catalysts with nitrogen-coordinated Cu sites due to the lower energy barriers of Cu-O(4) sites during ECR process. This work unravels the strong dependence of ECR selectivity on the Cu site coordination environment in crystalline porous catalysts, and provides a platform for constructing highly selective ECR catalysts.