Replacing Platinum with Tungsten Carbide (WC) for Reforming Reactions: Similarities in Ethanol Decomposition on Ni/Pt and Ni/WC Surfaces

Abstract

Selective reforming of biomass-derived oxygenates to produce hydrogen or syngas (H2 + CO) offers an attractive route for biomass utilization. As reported previously, the Ni/Pt(111) bimetallic surface, with one monolayer of Ni residing on top of Pt(111), showed enhanced activity in oxygenate reforming. However, the Ni/Pt(111) structure is not stable at high temperatures because of diffusion of Ni into bulk Pt. In the current study we explore the possibility of replacing the Pt substrate with tungsten monocarbide (WC) to prevent the diffusion of monolayer Ni into the bulk. We report a combined study using density functional theory (DFT), temperature programmed desorption (TPD), and high resolution electron energy loss spectroscopy (HREELS) to compare the reforming reaction of ethanol on Ni/Pt and Ni/WC surfaces. Strong similarities are observed in the reaction pathways of ethanol on monolayer Ni/Pt and Ni/WC, demonstrating the feasibility to replace Pt with WC and to use monolayer Ni/WC as active and less expensive reforming catalysts.