Molecular transition metal corrole as an efficient electrocatalyst for the heterogeneous CO2 electroreduction: A theory study

Carbon dioxide electrochemical reduction (eCO₂RR) has been regarded as an important solution for low-carbon economy. However, challenges remain for searching low-cost and high selectivity catalysts. Here, we investigated electrocatalytic activity of molecular catalysts containing transition metal single atom supported on corrole as the eCO₂RR catalysts (TM/SACC) by DFT. Various C₁ products can be produced on the 14 TM/SACC, including methane (CH₄), formic acid (HCOOH) and CO. We found CO and formic acid are major products on TM/SACC (TM = Ni, Pd, Zn, Cu, Au, Ag) at higher overpotentials, while methane are major eCO₂RR products on TM/SACC (TM = Mn, Cr, Nb, Mo, Zr, V, Ti, Cd) at lower overpotentials. Our studies indicate Mn/SACC gives high selectivity for methane formation. Due to the lowest overpotential value of 0.46 V, Mn/SACC can be a quite promising catalyst with excellent performance for reduction of CO₂ to methane along the most favorable pathway: CO₂ → COOH1 → CO1 → CHO1 → CH₂O1 → CH₂OH1 → CH₃OH1→CH₃1→CH₄1→CH₄(g), among which the hydrogenation of CHO1 to CH₂O1 and CH₃OH1 to CH₃1 and H₂O are the limiting-potential step and rate-determining step, respectively. The study shows corrole with different transition metal could adjust the catalytic performance of electrocatalysts, which offer a hopeful strategy for the design of molecular catalysts.