The Difference Se Makes: A Bio‐Inspired Dppf‐Supported Nickel Selenolate Complex Boosts Dihydrogen Evolution with High Oxygen Tolerance

• Published in: Chemistry : a European journal Vol. 24; no. 33; pp. 8275 - 8280
• Main Authors: Pan, Zhong‐Hua, Tao, Yun‐Wen, He, Quan‐Feng, Wu, Qiao‐Yu, Cheng, Li‐Ping, Wei, Zhan‐Hua, Wu, Ji‐Huai, Lin, Jin‐Qing, Sun, Di, Zhang, Qi‐Chun, Tian, Dan, Luo, Geng‐Geng
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 12-06-2018
• Subjects: Catalysis; Catalysts; Catalytic activity; Chemistry; DFT calculations; dihydrogen evolution; Electrochemistry; Hydrogen evolution; Hydrogen production; molecular catalysis; Molecular chains; Nickel; nickel(II) complexes; Oxygen; oxygen tolerance; Protons; Selenium
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201801893

Inspired by the metal active sites of [NiFeSe]‐hydrogenases, a dppf‐supported nickel(II) selenolate complex (dppf=1,1′‐bis(diphenylphosphino)ferrocene) shows high catalytic activity for electrochemical proton reduction with a remarkable enzyme‐like H2 evolution turnover frequency (TOF) of 7838 s−1 under an Ar atmosphere, which markedly surpasses the activity of a dppf‐supported nickel(II) thiolate analogue with a low TOF of 600 s−1. A combined study of electrochemical experiments and DFT calculations shed light on the catalytic process, suggesting that selenium atom as a bio‐inspired proton relay plays a key role in proton exchange and enhancing catalytic activity of H2 production. For the first time, this type of Ni selenolate‐containing electrocatalyst displays a high degree of O2 and H2 tolerance. Our results should encourage the development of the design of highly efficient oxygen‐tolerant Ni selenolate molecular catalysts.
Breaking new ground with Se: A dppf‐supported NiII diselenolate complex was synthesized and used as an efficient and robust oxygen‐tolerant dihydrogen‐production electrocatalyst. More importantly, the selenium‐based complex represents a 13‐fold enhancement in catalytic activity vs. the sulfur‐containing analogue. As indicated by DFT studies, the Se atom as a bio‐inspired proton relay plays a key role in facilitating protonation of a Ni‐hydride species and H2 evolution.