Understanding and controlling the location of acid sites in zeolites for their catalytic applications

Abstract: Zeolites are the most important heterogeneous catalysts used in a high number of large-scale chemical technologies. In spite of that, basic knowledge of aluminum location (catalytically active in acid catalyzed reactions) and especially control of aluminum location during synthesis and postsynthesis treatment have not been yet achieved. The proposed project is aimed at the employment of some structural types of zeolites that contain empty T-sites such as SSZ-74 or borosilicates (SSZ-33, SSZ-42) where is possible removal of boron from framework after synthesis followed by the insertion of aluminum cations. This procedure will enable the description of acidic properties of prepared zeolites (type of active site, their concentration and acid strength) related to the specific positions of aluminum, which is not possible for any known zeolite at present. Moreover, successful insertion of aluminum to the specific site will facilitate the control of the course of chosen catalytic reactions over precisely defined active center of zeolite. Thanks to that, detail description of differences in activity and selectivity of chosen zeolites, in contrast to classical zeolites, based on the knowledge of the behaviour of define active center will be possible.