The Rational Adjusting of Proton-feeding by Pt-doped FeP/C Hollow Nanorod for Promoting Nitrogen Reduction Kinetics

Abstract Following the guidance of nitrogenase, the natural iron-based catalysts with remarkably high activity in nitrogen reduction reaction (NRR) may be a talent option to develop artificial molecular mimics. However, the electrochemical NRR process of iron-based catalysts still suffers from the high overpotential, poor lifespan, and slow reaction kinetics of the hydrogenation process. Through a controllable etching and in-situ carbonating process, a Pt-doped FeP/C hollow nanorod catalysts was fabricated. Driven by the doped Pt atom, the catalyst solves the key kinetic problem about insufficient proton feeding in the process of nitrogen reduction, and actively transfers protons to intermediates of the hydrogenation steps in NRR. Moreover, the as-prepared catalyst presents the highest NH3 yield value of 10.22 μg h-1 cm-2 among multitudinous Fe based catalysts at lower potential of -0.05 V (vs. RHE) with an excellent Faraday efficiency (FE) of 15.3%, which is higher than FeP/C without the Pt-driven proton-feeding effect, the cathodic current density presents no significant change within 50 h. In addition, the density functional theory (DFT) and Attenuated total reflection surface-enhanced infrared absorption spectrum (ATR-SEIRAS) results verify the reaction path and protons-feeding kinetic process.