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

Abstract

• CO 2 RR performances on Fe single-atom catalysts coordinated by B atoms are explored. • Introduction of B atoms can promote multi-electron reduction reactions. • Linear relationship between limiting potential and O adsorption energy is revealed. • Fe magnetic moment and d-band center are key factors to improve CO 2 RR performance. Designing of effective electrocatalysts for electrocatalytic CO 2 reduction into value-added chemicals is the key to reducing CO 2 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 FeB x C y (x + y = 3 or 4), are constructed to systematically investigate the electrocatalytic CO 2 reduction reaction (CO 2 RR) based on density functional theory computations. Eight catalysts, including FeO 4 , are identified that can effectively activate CO 2 molecules and significantly inhibit competitive hydrogen evolution reaction (HER). Among them, FeB 2 C and FeB 2 C 2 h ( h represents a cis structure) show the higher CO 2 RR activity with the less negative limiting potentials of −0.24 and −0.40 V toward production of CH 4 , 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 CO 2 RR performance. By the coordinated B atom, an optimal adsorption strength of the reaction intermediates can be achieved on the FeB x C y surface, and thereby increasing CO 2 RR catalytic activity and product selectivity. FeB 2 C with more negative d-band center and the optimal Fe atomic magnetic moment shows the best CO 2 RR performance. These results reveal a great potential of coordination tuning for CO 2 RR, and provide a new theoretical perspective for rational design of high activity, selective CO 2 RR catalysts.