CO2 Fixation with Aryl Bromide toward Carboxylic Acid Enabled by Bifunctional CuAg Electrocatalysts

Electrocarboxylation of organic bromide with CO2 toward value-added carboxylic acid, which can be powered by renewable energy, provides one promising solution to facilitate the carbon balance. However, it is still a challenge to achieve high reactivity and selectivity without a sacrificial anode due to difficulties of activating CO2 and aryl bromide simultaneously and competitive reactions. Herein, we report an example of highly efficient electrocarboxylation of aryl bromides at the cathode along with oxygen evolution at the anode. Copper-silver nanowires as the cathodic catalysts demonstrate a Faraday efficiency of 98% for carboxylic acid production. Mechanism studies reveal that CO2 may be activated by Cu, and Ag species are responsible for the activation of aryl bromide and radical coupling process. This bifunctional activation model suppresses competitive hydrogenolysis and reductive coupling reactions of aryl bromide, thus achieving the high efficiency of electrocarboxylation.