Pinpointing the axial ligand effect on platinum single-atom-catalyst towards efficient alkaline hydrogen evolution reaction

• Published in: Nature communications Vol. 13; no. 1; pp. 6875 - 14
• Main Authors: Zhang, Tianyu, Jin, Jing, Chen, Junmei, Fang, Yingyan, Han, Xu, Chen, Jiayi, Li, Yaping, Wang, Yu, Liu, Junfeng, Wang, Lei
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 12.11.2022; Nature Publishing Group; Nature Portfolio
• Subjects: 119/118; 140/131; 140/133; 140/146; 147/135; 147/137; 147/143; 639/301/299/886; 639/638/675; 639/925/357; Affinity; Alkaline water; Catalysis; Catalysts; Catalytic activity; Correlation; Electron affinity; Energy efficiency; Green hydrogen; Homogeneity; Humanities and Social Sciences; Hydrogen; Hydrogen evolution reactions; Iron compounds; Irradiation; Ligands; multidisciplinary; Nickel compounds; Platinum; Science; Science (multidisciplinary); Single atom catalysts
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-022-34619-5

Developing active single-atom-catalyst (SAC) for alkaline hydrogen evolution reaction (HER) is a promising solution to lower the green hydrogen cost. However, the correlations are not clear between the chemical environments around the active-sites and their desired catalytic activity. Here we study a group of SACs prepared by anchoring platinum atoms on NiFe-layered-double-hydroxide. While maintaining the homogeneity of the Pt-SACs, various axial ligands (−F, −Cl, −Br, −I, −OH) are employed via a facile irradiation-impregnation procedure, enabling us to discover definite chemical-environments/performance correlations. Owing to its high first-electron-affinity, chloride chelated Pt-SAC exhibits optimized bindings with hydrogen and hydroxide, which favor the sluggish water dissociation and further promote the alkaline HER. Specifically, it shows high mass-activity of 30.6 A mgPt −1 and turnover frequency of 30.3  H 2 s −1 at 100 mV overpotential, which are significantly higher than those of the state-of-the-art Pt-SACs and commercial Pt/C catalyst. Moreover, high energy efficiency of 80% is obtained for the alkaline water electrolyser assembled using the above catalyst under practical-relevant conditions. Establishing robust structure/performance correlations is critical for the development of single-atom-catalysts with improved activity. Here, the axial ligand on Pt single-atom-catalyst is precisely adjusted and studied, showing that the ligand’s first electron affinity is crucial for the catalysis.