Boosting oxygen electrocatalytic performance of Cu atom by engineering the d-band center via secondary heteroatomic phosphorus modulation

Atomically  dispersed catalysts have been widely explored for some reactions, but it remains a challenge to modulate the electronic structure of the  center metal for enhancing the electrochemical activity. Herein, the electrochemical activity of copper single-atom catalyst (Cu SAC) was significantly improved by doping secondary heteroatomic phosphorus to engineer the d-band center of Cu atoms, which was named Cu SAC/P. In alkaline media, the Cu SAC/P-700 catalyst exhibited excellent oxygen reduction reaction (ORR) performance with a higher half-wave potential than Cu SAC-700, even better than the state-of-the-art 20 wt%  Pt/C 20 mV. The oxygen electroactivity coefficient was only 0.76 V, achieving good performance in zinc-air battery tests. Density functional theory calculations suggested that phosphorus effectively modulated the  density of states and the d-band center of Cu atoms. It improved the adsorption of the reaction intermediates and facilitated to trap them on Cu atoms, thus boosting the ORR activity of the catalyst.