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

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 mu g 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 on regulating 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 pi back-donation, lowering energy barriers of the rate-determining step, ultimately enhancing the overall NRR catalytic performance.

Automated summary

Researchers have prepared a nanoporous Ru-doped ReSe2 catalyst with controllable selenium vacancies by regulating the amount of Ru dopants. The catalyst exhibits excellent performance in the N2 reduction reaction, with high Faradaic efficiency and NH3 yield rate. The study also provides insights into the synergistic effect of Ru dopants and selenium vacancies on regulating the proton coverage on the ReSe2 surface and enhancing the overall catalytic performance.