Coordination-tuned Fe single-atom catalyst for efficient CO2 electroreduction: The power of B atom

Designing of effective electrocatalysts for electrocatalytic CO2 reduction into value-added chemicals is the key to reducing CO2 concentration and achieving carbon neutrality. However, achieving high activity and product selectivity simultaneously remains a significant challenge. Herein, a series of Fe single-atom catalysts coordinated by B atoms, namely FeBxCy (x + y = 3 or 4), are constructed to systematically investigate the electrocatalytic CO2 reduction reaction (CO2RR) based on density functional theory computations. Eight catalysts, including FeO4, are identified that can effectively activate CO2 molecules and significantly inhibit competitive hydrogen evolution reaction (HER). Among them, FeB2C and FeB2C2h (h represents a cis structure) show the higher CO2RR activity with the less negative limiting potentials of −0.24 and −0.40 V toward production of CH4, indicating the optimal content for doping B atoms. The activity mechanism shows that d-band center and magnetic moment of central Fe atom can be manipulated by rational modulating the coordinated B atoms to improve the CO2RR performance. By the coordinated B atom, an optimal adsorption strength of the reaction intermediates can be achieved on the FeBxCy surface, and thereby increasing CO2RR catalytic activity and product selectivity. FeB2C with more negative d-band center and the optimal Fe atomic magnetic moment shows the best CO2RR performance. These results reveal a great potential of coordination tuning for CO2RR, and provide a new theoretical perspective for rational design of high activity, selective CO2RR catalysts.