Developing cost-effective electrocatalysts for the ammonia oxidation reaction (AOR) is essential for advancing the hydrogen economy. Herein, we systematically investigate nine homonuclear dual-atom catalysts TM 2 @C 2 N (TM = Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt) anchored on a C 2 N monolayer for the AOR using density functional theory (DFT) calculations. Our results show that the Gerischer-Mauerer mechanism is the most kinetically favorable pathway. Among the screened catalysts, Fe 2 @C 2 N, Co 2 @C 2 N, Ru 2 @C 2 N and Os 2 @C 2 N are the most promising candidates with low limiting potentials of −0.93, −0.87, −0.89 and −0.95 V, respectively. These catalysts demonstrate superior hydrogen evolution reaction activity, suggesting their potential as bifunctional catalysts for hydrogen production via ammonia decomposition. We establish a volcano-type correlation between AOR limiting potential and NH 3 adsorption energy, confirming the latter as a robust descriptor. Furthermore, surface hydroxylation impairs AOR performance by weakening ∗NH 3 adsorption. This study provides theoretical guidance for designing high-performance AOR electrocatalysts. • TM 2 @C 2 N dual-atom catalysts are designed for ammonia oxidation reaction (AOR). • Fe 2 @C 2 N, Ru 2 @C 2 N, and Os 2 @C 2 N exhibit superior electrocatalytic AOR activity. • Ru 2 @C 2 N and Os 2 @C 2 N are promising bifunctional AOR/HER catalysts. • ∗NH 2 adsorption energy is a robust descriptor for AOR activity.
Wu et al. (Thu,) studied this question.