In-Situ Ft-Ir Spectroscopic Studies of Fuel Cell Electro-Catalysis: From Single-Crystal to Nanoparticle Surfaces

Abstract The work presented in this article shows the power of the variable temperature, in-situ FT-IR spectroscopy system developed in Newcastle with respect to the investigation of fuel cell electro-catalysis. On the Ru(0001) electrode surface, CO co-adsorbs with the oxygen-containing adlayers to form mixed CO + (2 × 2)–O(H) domains. The electro-oxidation of the Ru(0001) surface leads to the formation of active (1 × 1)–O(H) domains, and the oxidation of adsorbed CO then takes place at the perimeter of these domains. At 20°C, the adsorbed CO is present as rather compact islands. In contrast, at 60°C, the COads is present as a relatively looser and weaker adlayer. Higher temperature was also found to facilitate the surface diffusion and oxidation of COads. No dissociation or electro-oxidation of methanol was observed at potentials below approximately 950 mV; however, the Ru(0001) surface at high anodic potentials was observed to be very active. On both Pt and PtRu nanoparticle surfaces, only one linear bond CO adsorbate was formed from methanol adsorption, and the PtRu surface significantly promoted both methanol dissociative adsorption to CO and its further oxidation to CO2. Increasing temperature from 20° to 60°C significantly facilitates the methanol turnover to CO2. Keywords: Carbon monoxideFuel cell electro-catalysisIn-situ FT-IR spectroscopyMethanolPlatinumRuthenium Acknowledgments Financial support from the EPSRC and the EU (under Framework 5) is gratefully acknowledged.