Revealing a Power-Law Relationship Between Dopant-Metal Distance and Adsorption Free Energy Change for Precise Optimization of ORR on TM 1 N 4 Monoatom Catalysts

Abstract

Studying the influence of dopant-transition metal (TM) distance (d TM-N ) on electronic structures of active centers is beneficial for fine-tuning catalytic performance. In this work, oxygen reduction reaction activity and selectivity of TM 1 N 4 @carbon (TM: Fe, Co and Ni) were modulated by adjusting d TM-N values using density functional theory. Results show that nitrogen doping lowers d-band center thereby enhancing d-p orbital hybridization, which in turn leads to an increase in the adsorption free energy of intermediates. Difference in adsorption free energy (ΔG doped -ΔG pristine ) is determined by the nature of adsorbed species and type of TM, with power-law relationships identified between these factors. Catalytic performance is primarily governed by the intrinsic chemical activity of TM atoms and further optimized through precise control of d TM-N . With appropriate nitrogen doping,Co 1 N 4 @carbon exhibits low overpotentials for two-electron path (0.018 and 0.026 V when nitrogen are respectively doped at positions 1 and 2). This approach offers a promising strategy for the design of high-activity and selectivity catalysts.