2017 Spring Meeting of the Korean Chemical Society
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.