(127b) The Role of Site Composition and Confinement On Catalyst Activity and Selectivity

Understanding how to control catalyst activity and selectivity is the key in making progress towards catalyst design. Catalytically active sites may occur as isolated species or as part of an extended solid. In both cases the activity and selectivity of a site is strongly dependent not on only its composition, but also the structure and composition of its surroundings. Recent work has also shown that the spatial confinement and the presence of non-catalytic species can further affect the performance of active sites. This talk will illustrates these ideas using examples related to the oligomerization of alkenes catalyzed single Ni²⁺ sites, aldol condensation catalyzed by supported alkyl amines, cracking and dehydrogenation of alkanes catalyzed by zeolite Brønsted-acid sites, and alkene oxidation catalyzed by mixed metal oxides. It will be shown that insights into the factors that are most critical for defining site activity and selectivity can be identified by through the combined use of experimental and theoretical methods.