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

Abstract

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.