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Surface phase diagrams based on density functional theory (DFT) calculations are used to identify stable surface phases present during the oxidation of fuel-cell-relevant organic compounds on Pt-Ru catalysts. The presence of adsorbed CO and O under operando conditions triggers changes in the local structure and composition of the metal alloy’s surface. We find that a Ru-rich Pt-Ru surface stabilizes the mixed CO-O adsorbate phases that we expect to be most conducive to stable and efficient catalyst operation. The predicted surface structures and adsorbate coverages are confirmed by operando X-ray absorption spectra (XAS).

The thermal diffusivity, κ , and conductivity, λ , of Ca-doped stabilized zirconia were simultaneously measured up to 5.3 GPa and 700 K employing the pulse transient method. From κ and λ , heat capacity, C , was also derived. The temperature dependences of κ and λ at 5.3 GPa were found to be very small, and may be due to oxygen ion conduction. The present data are especially useful for designing a high-pressure cell in a Kawai-type apparatus, where Ca-doped stabilized zirconia has been frequently used as thermal insulator around a heater.