Metal-Support Interaction between Platinum and Mesoporous Molybdenum Carbide for Efficient Alkaline Hydrogen Evolution Reaction

Abstract

More sluggish reaction kinetics and inferior stability of Pt catalysts for alkaline hydrogen evolution reaction (HER) compared to acidic HER represent a great challenge in alkaline electrolyzer technologies, which is an essential element in sustainable hydrogen economy. In this presentation, we have synthesized mesostructured molybdenum carbide supported Pt (Pt/MMC) catalyst for alkaline HER, and demonstrate that the alkaline HER activity of Pt nanoparticle catalyst can be promoted by exploiting metal−support interaction between Pt nanoparticles and molybdenum carbide support. X-ray absorption near edge structure and X-ray photoelectron spectroscopy analyses revealed that Pt atoms exist in more reduced oxidation states in Pt/MMC than those in commercial Pt/C catalysts (Pt nanoparticles dispersed on carbon black). Compared to carbon black support, MMC could donate more electrons to nearby Pt atoms, elevating d-band center of Pt. Electrochemical measurements demonstrated that mass activity and specific activity of the Pt/MMC are 1.6- and 1.5-fold higher than those of commercial Pt/C with the same Pt loading, respectively. This result suggested that the adsorption/desorption strength of reactants (i.e. hydrogen) and reaction intermediates (i.e. hydroxide) was adjusted to the optimized level for efficient HER in alkaline media.