Regulating the Local Charge Distribution of Ni Active Sites for Electrosynthesis of Nitriles Coupled with H2 Production

The selective electrosynthesis of nitriles from organic amines coupled with hydrogen generation provides a promising strategy to produce valuable chemicals via a sustainable route. In this study, we design Ru (0.49 wt %)-modified Ni2P nanobelt arrays as an efficient bifunctional catalyst for the selective electro-oxidation of benzylamine into high value-added benzonitrile coupled with hydrogen generation in alkaline solution. The Ru–Ni2P/NF delivers a high Faradaic efficiency of approximately 96.3% for benzonitrile production. The electrolyzer using Ru–Ni2P/NF for both anodic benzonitrile and cathodic H2 production requires a low voltage of 1.47 V for achieving a current density of 50 mA cm–2, allowing the integration of a 1.50 V solar cell panel as a renewable energy source input. This coproduction system is immune from mixed H2/O2 hazards and benefits from easy collection of benzonitrile products for its water insolubility. The X-ray absorption spectroscopy and theoretical calculations reveal that Ru can attract electrons from adjacent Ni atoms and facilitate the formation of high-valence Ni active sites, favoring C–NH2 bond activation for dehydrogenation to C≡N bonds, thus accelerating benzylamine oxidation reaction. The combination of electrochemical measurements and in situ Raman and FTIR spectroscopies uncovers in situ formed NiOOH as the catalytically active sites that are promoted by Ru doping and identifies the reaction pathway. This work provides an appealing strategy on infinitesimal noble metal modification of bifunctional electrocatalysts for selective nitrile electrosynthesis and concurrent hydrogen production with insights into catalyst design and catalytic mechanisms.