Selective CO Electroreduction to Multi-Carbon Products on Organic-Functionalized CuO Nanoparticles by Local Micro-Environment Modulation.

Surface functionalization of Cu-based catalysts has demonstrated promising potential for enhancing the electrochemical CO reduction reaction (CORR) toward multi-carbon (C) products, primarily by suppressing the parasitic hydrogen evolution reaction and facilitating a localized CO/CO concentration at the electrode. Building upon this approach, we developed surface-functionalized catalysts with exceptional activity and selectivity for electrocatalytic CORR to C in a neutral electrolyte. Employing CuO nanoparticles coated with hexaethynylbenzene organic molecules (HEB-CuO NPs), a remarkable C Faradaic efficiency of nearly 90% was achieved at an unprecedented current density of 300 mA cm, and a high FE (> 80%) was maintained at a wide range of current densities (100-600 mA cm) in neutral environments using a flow cell. Furthermore, in a membrane electrode assembly (MEA) electrolyzer, 86.14% FE was achieved at a partial current density of 387.6 mA cm while maintaining continuous operation for over 50 h at a current density of 200 mA cm. In-situ spectroscopy studies and molecular dynamics simulations reveal that reducing the coverage of coordinated K⋅HO water increased the probability of intermediate reactants (CO) interacting with the surface, thereby promoting efficient C-C coupling and enhancing the yield of C products. This advancement offers significant potential for optimizing local micro-environments for sustainable and highly efficient C production.