Highly Selective CO Electroreduction to C Products over CuO-Decorated 2D Metal-Organic Frameworks with Rich Heterogeneous Interfaces.

The electroreduction of carbon dioxide into high-value-added products is an effective approach to alleviating the energy crisis and pollution issues. However, there are still significant challenges for multicarbon (C) product production due to the lack of efficient catalysts with high selectivity. Herein, a Cu-rich electrocatalyst, where CuO nanoparticles are decorated on two-dimensional (2D) Cu-BDC metal-organic frameworks (MOFs) with abundant heterogeneous interfaces, is synthesized for highly selective CO electroreduction into C products. A high C Faradaic efficiency of 72.1% in an H-type cell and 58.2% in a flow cell are obtained, respectively. The heterogeneous interfaces of CuO/Cu-BDC can optimize the adsorption energy of reaction intermediates during CO electroreduction. An in situ infrared spectroscopy study indicates that the constructed interfaces can maintain the particular distribution of Cu valence states, where the C-C coupling is promoted to efficiently produce C products owing to the stabilization of *CHO and *COH intermediates.