Altering Ligand Fields in Single-Atom Sites through Second-Shell Anion Modulation Boosts the Oxygen Reduction Reaction

• DOI: 10.1021/jacs.1c11331
• Publication Date: 2022-01-28T16:35:00Z
• Authors: Jiayi Qin; Hui Liu; Peichao Zou; Rui Zhang; Chunyang Wang; Huolin L. Xin
• Keywords: 01 natural sciences; 0104 chemical sciences

Single-atom catalysts based on metal-N4 moieties and anchored carbon supports (defined as M-N-C) are promising for oxygen reduction reaction (ORR). Among those, M-N-C with 4d 5d transition metal (TM4d,5d) centers much more durable not susceptible to the undesirable Fenton reaction, especially compared 3d ones. However, ORR activity of these TM4d,5d-N-C is still far from satisfactory; thus far, there few discussions about how accurately tune ligand fields single-atom TM4d,5d sites in order improve their catalytic properties. Herein, we leverage Ru-N-C a model system report an S-anion coordination strategy modulate catalyst's structure performance. The S anions identified bond N atoms second shell Ru centers, which allows us manipulate electronic configuration central sites. S-anion-coordinated catalyst delivers only but also outstanding long-term durability, superior those commercial Pt/C most near-term catalysts. DFT calculations reveal that high attributed lower adsorption energy intermediates at Metal-air batteries using this cathode side exhibit fast kinetics excellent stability.