P‐Block Atomically Dispersed Antimony Catalyst for Highly Efficient Oxygen Reduction Reaction

Abstract Main‐group ( s ‐ and p ‐block) metals are generally regarded as catalytically inactive due to the delocalized s / p ‐band. Herein, we successfully synthesized a p ‐block antimony single‐atom catalyst (Sb SAC) with the Sb−N 4 configuration for efficient catalysis of the oxygen reduction reaction (ORR). The obtained Sb SAC exhibits superior ORR activity with a half‐wave potential of 0.86 V and excellent stability, which outperforms most transition‐metal (TM, d ‐block) based SACs and commercial Pt/C. In addition, it presents an excellent power density of 184.6 mW cm −2 and a high specific capacity (803.5 mAh g −1 ) in Zn–air battery. Both experiment and theoretical calculation manifest that the active catalytic sites are positively charged Sb−N 4 single‐metal sites, which have closed d shells. Density of states (DOS) results unveil the p orbital of the atomically dispersed Sb cation in Sb SAC can easily interact with O 2 ‐ p orbital to form hybrid states, facilitating the charge transfer and generating appropriate adsorption strength for oxygen intermediates, lowering the energy barrier and modulating the rate‐determining step. This work sheds light on the atomic‐level preparing p ‐block Sb metal catalyst for highly active ORR, and further provides valuable guidelines for the rational design of other main‐group‐metal SACs.