Surface Self-Reconstruction of Fe-Ni_3S_2 Electrocatalyst for Value-Generating Nitrile Evolution Reaction to Drive Efficient Hydrogen Production

摘要

Thermodynamically favorable electrooxidation of organics coupled withhydrogen production as an alternative to overall water splitting is rapidlydeveloping due to low energy consumption and high value. But understandingthe relationship between catalyst reconstruction and performance indepth remains a challenge. Herein, DFT calculations are used as a theoreticalguide to adjust the local coordination environment and electronic structureof Ni_3S_2 by Fe doping, which promotes the self-reconstruction of catalyst andnitrile evolution reaction performance. The overall reaction of benzylamineelectrooxidation coupled with hydrogen production achieves a 14.5-foldimprovement in hydrogen production compared to water electrolysis at thesame potential, almost completely converting benzylamine to high-valuebenzonitrile (99% product yield). In situ spectroscopy and X-ray absorptionfine structure spectroscopy demonstrate that the excellent electrocatalyticperformance due to Fe doping induces surface self-reconstruction of Ni_3S_2 toNiOOH at low potential, and significantly reduces the rate-determining stepenergy barriers for CN bonds to C≡N bonds. This work provides theoreticalguidance in designing and preparing efficient catalysts for the electrosynthesisof nitrile compounds coupled with hydrogen production