Ultrasmall molybdenum carbide nanocrystals coupled with reduced graphene oxide supported Pt nanoparticles as enhanced synergistic catalyst for methanol oxidation reaction

Abstract

Ultrasmall molybdenum carbide (MoC) nanocrystals coupled with reduced graphene oxide (RGO) hybrid was successfully synthesized and applied as support for Pt nanoparticles (Pt/MoC-RGO). Compare to the commercial Pt/C, the Pt/MoC-RGO catalyst show remarkable enhanced electrocatalytic activity for methanol oxidation reaction (MOR) in direct methanol fuel cells (DMFCs). The peak current density of Pt/MoC-RGO is 2.4 times of Pt/C. The Pt/MoC-RGO also shows a significant improved CO resistance ability, which likely originates from the abundant Pt-MoC-RGO three-phase interfaces in Pt/MoC-RGO. The long-term stability results show that the electrochemical durability of the Pt/MoC-RGO for MOR is much better than Pt/C, making it a promising next generation electrocatalysts in DMFCs. X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS) analyses reveal the strong synergetic chemical coupling interaction between the Pt nanoparticles and MoC-RGO, which result in significantly enhanced electrocatalytic activity for MOR.