Dicopper(I) Sites Confined in a Single Metal-Organic Layer Boosting the Electroreduction of CO to CH in a Neutral Electrolyte.

It is challenging and important to achieve high performance for an electrochemical CO reduction reaction (eCORR) to yield CH under neutral conditions. So far, most of the reported active sites for eCORR to yield CH are single metal sites; the performances are far below the commercial requirements. Herein, we reported a nanosheet metal-organic layer in single-layer, namely, [Cu(obpy)] (, Hobpy = 1-[2,2']bipyridinyl-6-one), possessing dicopper(I) sites for eCORR to yield CH in a neutral aqueous solution. Detailed examination of revealed high performance for CH production with a faradic efficiency of 82(1)% and a current density of ∼90 mA cm at -1.4 V . reversible hydrogen electrode (RHE). No obvious degradation was observed over 100 h of continuous operation, representing a remarkable performance to date. Mechanism studies showed that compared with the conventional single-copper sites and completely exposed dicopper(I) sites, the dicopper(I) sites in the confined space formed by the molecular stacking have a strong affinity to key C intermediates such as *CO, *CHO, and *CHO to facilitate the CH production, yet inhibiting C-C coupling.