Boosting protonation kinetics for ammonia electrosynthesis on Ru sites embedded in nanoporous ReSe2

Abstract

Electrocatalytic N2 reduction reaction (NRR) is a promising approach for renewable NH3 production but is constrained by poor activity and selectivity, owing to the sluggish hydrogenation kinetics. Herein, we prepare a nanoporous Ru-doped ReSe2 (NP Ru-ReSe2) with controllable selenium vacancies by regulating the amount of Ru dopants. The catalyst exhibits excellent the NRR performance, which affords a high Faradaic efficiency of 22.7% and NH3 yield rate of 19.41 μg h−1 mg−1 at –0.4 V versus a reversible hydrogen electrode(RHE). In situ attenuated total reflectance–surface-enhanced infrared absorption spectroscopy studies combined with theoretical calculations unravel that a clear synergistic effect of Ru dopants and selenium vacancies onregulating the proton (H*) coverage on the ReSe2 surface to accelerate the proton-coupled processes as NN → NNH. while N2 dissociation becomes exothermic over the Ru active sites via Ru-to-N2 π back-donation, lowering energy barriers of the rate-determining step, ultimately enhancing the overall NRR catalytic performance.