Engineering Ru and Ni sites relay catalysis and strong metal-support interaction for synergetic enhanced electrocatalytic hydrogen evolution performance

Abstract

Electrocatalytic hydrogen evolution is the crucial technology of renewable energy conversion and fuel production in the future energy system. However, its catalytic performance is often limited by multiple step requirements of alkaline HER and trade-off between the activity and stability. Water dissociation, as a fundamental step in alkaline HER, directly impacts the overall efficiency of electrocatalytic hydrogen evolution. Here, the Ru-doped Ni nanoparticles coated with graphite carbon shell in carbon nanofiber (Ru₁Ni₆/CNF) was constructed by electrospinning and pyrolysis process. By changing the ratio of Ru to Ni, the synergistic effect between Ru site and Ni site was amplified, and the relay synergistic reaction between Ru site and Ni site was realized. Strong metal-support interaction (SMSI) formed between Ru-doped Ni nanoparticles and graphite carbon shell not only protects the catalyst from the loss of specific surface area caused by thermal agglomeration, but also promotes charge transfer. Graphite carbon shell can protect the catalyst surface from (electro-) chemical corrosion. The Ru₁Ni₆/CNF exhibits a low overpotential of 14 mV at 10 mA cm⁻² and shows excellent stability over 400 h in 1 M KOH solution. DFT shows that the Ru site has high adsorption and desorption efficiency for water, which is essential for the water dissociation step in alkaline HER, while Ni site promotes hydrogen recombination. The performance of the dual sites relay catalyst is comparable to that of the commercial precious metal catalyst. This study provides a prospect for the design of multi-sites and multifunctional component cooperative reaction catalysts.