This application seeks to discover whether the catalyst handling protocols refined for INS measurements of a variety of heterogeneous catalytic systems can be further exploited to examine the hydrocarbonaceous overlayers that form over hydrogenation catalysts. These overlayers control selectivity profiles. The proposal aims to use the sensitivity of the MAPS spectrometer to obtain the vibrational spectrum of an alumina-supported palladium catalyst that is active for the selective hydrogenation of propyne to propene. Moreover, following recent favourable results on an analogous system [RB1010131], spectra will be acquired at room temperature as well as the more usual cryogenic temperatures. These latter measurements offer the opportunity to perform INS operando measurements on working catalysts.