Fullerene Promotes CO Reduction to Methanol by a Cobalt(II) Phthalocyanine Electrocatalyst.

Heterogenization of molecular electrocatalysts offers an attractive way to improve the catalytic selectivity and efficiency of CO conversion to liquid fuels. Herein, we employ density functional theory to compare the mechanism of CORR by a cobalt(II) tetra(amino)phthalocyanine (Co(II)Pc(NH)) electrocatalyst with and without the presence of fullerene support. Our DFT calculations suggest that the CO reduction mechanism is initiated by a metal-based electron reduction followed by subsequent CO nucleophilic addition, electron transfer, proton transfer, water dissociation, and proton-coupled electron transfer steps that lead to CO and methanol formation. We show that graphitic interactions between the Co(II)Pc(NH) electrocatalyst and C support selectively improve the CORR to methanol at mild potentials. The undesirable hydrogen evolution reaction (HER) was also investigated for both electrocatalysts and proceeds via the protonation of the cobalt metal center over the nitrogen atom in the inner ring. The competition between the HER and the CORR was improved in favor of CO and methanol formation using the Co(II)Pc(NH)@C electrocatalyst. Overall, our results suggest C as a promising graphitic support for molecular electrocatalysts integration for CO catalysis.