Breaking Barriers in Zeolite Synthesis via ZnO-Assisted Interzeolite Conversion for Enhanced Catalysis

Interzeolite Conversion (IZC) can overcome kinetic hurdles toward exceptional phases by taking advantage of the selective dissolution of crystalline ones. Controlled dissolution of a siliceous mordenite (MOR) in the presence of ZnO enables us to ‘catch’ a zincosilicate ferrierite (FER) topology. Structural characterization proves that defect engineering achieved from a mild post-treatment can tune composition and properties ranging from a Zn-containing FER with Si/Al and Si/Zn ratios of 170 and 36 to a high-silica FER with a Si/Al ratio of 170 and Si/Zn ratio of 700, which is challenging to reach from one-step synthesis in hydroxide media. The extent of acid washing can regulate the framework Zn species toward a Lewis acid catalyst and an almost nonacidic high-silica counterpart. Along the way, we provide ample new insights into the influence and role of zinc heteroatom on the kinetics of IZC. Due to the custom textural properties obtained by IZC, post-treatment, and also by exhibiting Lewis acidity with less Bro̷nsted acidity, Zn-FER shows enhanced selectivity and long lifetime for dimethyl ether (DME) production in the CO 2 hydrogenation to hydrocarbons reaction.