Revealing the Synergistic Enhancement Effect of Dual Metal RuFe(Co) Sites for Bifunctional Oxygen Catalysis
Xuyan Zhou, Shufen Chu, Zeyu Jin, Kailong Hu, Pan Liu, Hua‐Jun Qiu, Xi Lin
Abstract
Modifying the geometric and electronic structures of metal–N–C single-atom catalysts to improve their catalytic activities is quite desirable and challenging. Here, theoretical analysis and experiment indicate the inherent synergistic effect of dual metal sites in N-doped carbon for bifunctional ORR and OER. Specifically, introducing Ru to generate RuFe–N–C or RuCo–N–C double-atom catalysts (DACs) can significantly enhance the bifunctional ORR/OER activities of Fe(Co) and Ru sites, exceeding the equivalent single metal Fe(Co)–N–C and Ru–N–C. Investigations of a series of RuM–N–C DACs reveal that the intriguing synergistic effect results from the modified charge density and d-band center by combining two optimized metal atoms, which affects adsorption energies of intermediates and catalytic activity. Based on these theoretical guidelines, RuFe–N–C is synthesized using a bimetal MOF as the precursor, and it exhibits exceptional ORR/OER activities in alkaline media with a small Δ E of 0.63 V, significantly outperforming Fe–N–C, Ru–N–C, and even commercial Pt/C-RuO 2 .