p–d Orbital hybrid Ni–Al NC catalyst withstanding potential variations in highly selective electro-reduction of CO2 to CO

Abstract

The practical application of CO₂ electroreduction to CO driven by renewable electricity should simultaneously meet the requirements of low overpotential, high CO faradaic efficiency (FE), and low cost. Herein, a new strategy is reported to construct a porous nanoflower Ni–Al NC catalyst with excellent catalytic activity via p–d orbital hybridization of Al and Ni. The optimized Ni–Al NC catalyst exhibits an outstanding CO₂ electroreduction activity with the maximum CO FE of 98%, low onset potential of −0.5 V vs. RHE, and wide FE_CO plateau (>90% from −0.7 to −1.0 V vs. RHE), showing great promise for practical applications. The experimental results showed that the p–d hybrid Ni–Al NC catalyst not only enriched its reaction sites but also withstood potential changes in the highly selective reduction of CO₂ to CO. This study provides a catalyst design strategy for the efficient electrocatalytic reduction of CO₂ to CO under varying potentials.