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 aim is to obtain the vibrational spectrum of an alumina-supported palladium catalyst that is active for the selective hydrogenation of propyne to propene. Our previous proposal (RB1110302) used MAPS for this work but we were unable to detect any surface species, despite having clear evidence that the chemistry proceeded as expected. In this proposal, we have the same aim but will use MERLIN in order to provide the maximum sensitivity available.