Vinyl acetate is used on the million tonnes per year scale for the production of various grades of polyvinyl acetate, a component in paper, adhesive and textile applications. For its synthesis, supported palladium catalysts are used in the Wacker-Hoechst process. Recently, we have measured the proton dynamics of a PdAu/SiO2 catalyst and have compared them with Pd/C catalysts. The apparent normalized integrated area due to beta-PdH is very large, twice that found for the Pd/C samples. It is likely that there are contributions from other species, e.g. OH generated by spillover onto the silica support, that are wrongly included in the area. Hydrogen on a series of catalysts: Pd/SiO2, Au/SiO2 and PdAu/SiO2 will be studied with MAPS, which will enable us to assess the effect on the silica hydroxyls as well as observe the state of hydrogen on or in the metal.