The Promotional Effect of Na on Ru for pH-Universal Hydrogen Evolution Reactions

Alkali metals, as ideal electron donors, can effectively regulate the valence state distribution of the host metals. Nevertheless, no studies have reported the application of alkali metal promoters in the hydrogen evolution reaction (HER). Here, we designed an efficient and wide pH-universal hydrogen evolution catalyst that utilizes alkali metal to control the valence, size, and dispersion of Ru NPs. The experimental results reveal that the alkali metal additives contribute to the dispersion and stabilization of metallic Ru. More importantly, the interaction between Na and Ru regulates the distribution of Ru valence states and helps to form more active components of Ru-0. Additionally, NaCl functioned as an in situ template to assist the construction of a porous carbon skeleton promotes mass transfer and exposes more active sites, further promoting the synergistic effect of Ru and Na. As a result, the optimal Ru-0.3/C-800 delivers high efficiency for HER with an overpotential as low as 29 mV in 1.0 M KOH and 83 mV in 0.5 M H2SO4 under 10 mA cm(-2). Particularly, the catalytic performance of Ru-0.3/C-800 even outbalanced that of commercial Pt/C in an alkaline medium. This rational construction strategy opens up new avenues for obtaining superior pH-universal electrocatalysts.

Automated summary

Alkali metals are used to control the valence, size, and dispersion of Ru NPs in a pH-universal hydrogen evolution catalyst. The alkali metal additives contribute to the dispersion and stabilization of metallic Ru, and the interaction between Na and Ru regulates the distribution of Ru valence states. Additionally, NaCl acts as a template to promote mass transfer and expose more active sites, further enhancing the catalytic performance of Ru.