Remarkably efficient PtRh alloyed with nanoscale WC for hydrogen evolution in alkaline solution

摘要

Crucial to scalable hydrogen generation in modern technology is developing the well designed catalysts with remarkably high activity and excellent stability. In this work, nanoscale tungsten carbide hybrid materials (WC/C) was synthesized by intermittent microwave heating method (IMH), and then the alloyed Pt9Rh-WC/C catalysts were prepared by impregnation-reduction method followed by subsequent thermal annealing under N-2 atmosphere. Characterization of the as-formed alloy catalysts by transmission electron microscopy (TEM) confirmed that the PtRh nanoparticles were uniformly distributed on the WC/C hybrid materials. The cyclic voltammograms (CV) method was used to study their catalytic performance for hydrogen evolution reaction (HER) in 0.1 mol L-1 KOH aqueous solution. The results displayed that the HER activities of WC/C, Pt/C, Pt9Rh/C and Pt9RhWC/C increased subsequently, and the overpotentials were 500, 122, 105 and 90 mV at a current density of 8 mA cm(-2). The improved catalytic activity of Pt9Rh-WC/C for HER was ascribed to the addition of rhodium and tungsten carbide, which might decrease the Pt-H binding energy in alkaline solution. Meanwhile, it also displayed excellent stability in the accelerated durability test. This work thereby provides a practical strategy for making costeffective catalysts for scalable hydrogen production. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.