Phosphorus/Sulfur-Modulated p-Band Center of Pentagonal Carbon for Efficient Oxygen Reduction Reaction

Abstract

Nonmetallic carbon-based materials are highly promising catalysts for the electrochemical oxygen reduction reaction (ORR). Pentagonal carbon motifs, among their most active sites, significantly accelerate the kinetically sluggish ORR. However, their intrinsic activity remains inferior to that of metal-based sites due to a lack of effective electronic modulation strategies. Herein, theoretical modeling predicts that cooperative phosphorus and sulfur heteroatom coordination synergistically tunes the p-band center of pentagonal carbon, inducing collective contributions of local defects, coordination environments, and charge transfer. This multifactor electron-regulation engineering breaks the linear scaling relationship, realizing asynchronous optimization between the key ORR intermediates and the adsorption energies. Guided by this insight, we developed a template-confined synthesis strategy to precisely construct an electrocatalyst with phosphorus/sulfur cocoordinated pentagonal carbon sites (P/S- p C). This catalyst promotes efficient four-electron ORR, achieving a kinetic current density at 0.80 V (vs RHE) that is 19.7 times higher than that of pristine pentagonal carbon and 4.2 times higher than commercial Pt/C. The exceptional ORR activity translates to a zinc–air battery peak power density of 204.9 mW cm –2, exceeding the Pt/C-based cell by over 1.5 times. Combined density functional theory calculation and in situ surface-enhanced infrared absorption spectroscopy reveal that P/S coincorporation modulates the carbon coordination environment, enhancing electron transfer from P/S toward carbon sites, which largely modulates the electronic structures, thereby optimizing the activation and protonation of oxygenated intermediates and lowering the energy barrier of *OH desorption. This work establishes a precise electronic structure modulation strategy for designing highly active and stable carbon-based ORR catalysts.