This is a new application, made under the Catalytic Science in the Harwell Research Centre initiative that seeks to investigate whether INS could provide new information on a topic of large economic significance. Namely, the applicants request 2 days on MERLIN to discover whether INS can contribute to the active debate on the presence and role of a ¿hydrocarbon pool¿ in a certain area of zeolite catalysis. Catalytic cracking operations in oil refineries typically use high-silica zeolite catalysts, which are prone to deactivation through coke formation. This proposal seeks to discover whether INS is capable of detecting the presence of a ¿hydrocarbon pool¿, that is implemented in the route to forming coke. If the proposed preliminary studies are informative, the applicants will work together to incorporate INS in to their on-going investigations of these most adaptable catalysts.