Proton conducting mixed metal oxides are a developing area of interest to the fuel cell community as potential electrolyte materials for intermediate temperature (400-600oC) fuel cells. These materials operate via the bulk incorporation, and subsequent Grotthuss mechanism hopping, of protons through the bulk. While significant work has been performed within the fuel cell community to optimize ionic transport, to the best of our knowledge, there have been no previous reports utilizing these proton conductors as catalytic supports for hydrogenation or dehydrogenation reactions. In this work we utilize barium cerates and zirconates and oxide supports for chromium catalysts in ethane dehydrogenation, and for Pt/Co nanoparticle supports in CO2 methanation.
In both cases we report significant (up to one order of magnitude) improvement in reaction rate and improvements in reaction selectivity when compared to traditional support materials. This is attributed to increased hydrogen spillover, incorporation and transport within the bulk of the proton conducting support. The improvement in activity follows the trend of increasing proton conductivity as we vary the composition of the support. The catalysts are characterized in terms of activity and their structure and composition probed by X-ray diffraction, X-ray Photoelectron Spectroscopy, High Sensitivity Low Energy Ion Scattering, and High Resolution Transmission Electron Microscopy.