Highly Selective Electrocatalytic CO2 Reduction to Methanol on Iridium Dioxide with CO* Spectators

Abstract Iridium dioxide has emerged as a promising anode family for electrocatalytic reduction of CO 2 . Herein, the catalytic mechanism of CO 2 reduction reaction (CO 2 RR) on the IrO 2 (110) electrocatalyst model has been assessed using density functional theory (DFT) calculations. The CO * spectator on the IrO 2 (110) is the crucial factor, which directly affects the binding free energy of the reaction intermediates by means of the different ratios of CO * spectator models. Our results showed that the CO * spectator may have a great promotion effect on the methanol production, and it always maintains low sensitivity on the CO 2 reduction to methane reaction. The onset potentials for reducing to methanol and methane are −0.32 V‐RHE and −0.68 V‐RHE, respectively, at a CO * coverage of 50 %, which means that providing an appropriate CO * coverage can improve the selectivity of CO 2 catalytic reduction to methanol tremendously. It is worth noting that the intermediate CH 3 O * +OH * , which plays a vital role in the major pathways to produce methanol and methane, is a branch point that led to the formation of two products. Although both subsequent protonation processes are exothermic, the path to methanol production is more favorable than that of CH 4 formation. These results demonstrate that iridium dioxide should be a good CO 2 RR catalyst, and the CO * spectator also exhibits an enhanced effect on the selectivity of CO 2 reduced to alcohol products.