Promoting CO 2 Electroreduction to Acetate by an Amine-Terminal, Dendrimer-Functionalized Cu Catalyst.

Acetate derived from electrocatalytic CO 2 reduction represents a potential low-carbon synthesis approach. However, the CO 2 -to-acetate activity and selectivity are largely inhibited by the low surface coverage of in situ generated *CO, as well as the inefficient ethenone intermediate formation due to the side reaction between CO 2 and alkaline electrolytes. Tuning catalyst microenvironments by chemical modification of the catalyst surface is a potential strategy to enhance CO 2 capture and increase local *CO concentrations, while it also increases the selectivity of side reduction products, such as methane or ethylene. To solve this challenge, herein, we developed a hydrophilic amine-tailed, dendrimer network with enhanced *CO intermediate coverage on Cu catalytic sites while at the same time retaining the in situ generated OH - as a high local pH environment that favors the ethenone intermediate toward acetate. The optimized amine-network coordinated Cu catalyst (G 3 -NH 2 /Cu) exhibits one of the highest CO 2 -to-acetate Faradaic efficiencies of 47.0% with a partial current density of 202 mA cm -2 at -0.97 V versus the reversible hydrogen electrode.