RhRu alloyed nanoparticles confined within metal organic frameworks for electrochemical hydrogen evolution at all pH values

Abstract

As an effective way to generate high-purity hydrogen through water electrolysis, electrochemical hydrogen evolution reaction (HER) underpins various clean-energy technologies. Nevertheless, most of the currently reported HER catalysts only exhibited good activity in a narrow pH range (e. g. in acid electrolyte). Thence, developing high-performance electrocatalysts for HER at all pH values is significant and imperative. Herein, we report an active electrocatalyst of RhxRu100-x@UiO-66-NH2 (x denotes the initial atomic percentage of Rh in RhRu alloys) by in-situ confining RhRu binary alloys within metal-organic framework (MOF) of UiO-66-NH2. Among the RhxRu100-x@UiO-66-NH2 samples, Rh50Ru50@UiO-66-NH2 exhibited the most outstanding HER performance at all pH values, as well as comparable activity and outperformed stability to the commercial Ru/C and Pt/C catalysts. In HER tests, Rh50Ru50@UiO-66-NH2 displayed an overpotential of 77 mV, 114 mV and 177 mV at the current density of 10 mA cm−2 in 0.5 M H2SO4 (pH = 0.53), 1 M PBS (pH = 7) and 1 M KOH (pH = 14) solutions, respectively. The strategy for confining metal nanoparticles within the cavities of MOFs can enrich the toolbox for design and construction of low cost, efficient, and environment-friendly catalysts for hydrogen production toward clean energy applications.