Investigation of the hydrocarbon pool species responsible for methanol to olefin catalysis on acidic zeolite and zeotype catalysts

The main theme of this dissertation is the study of aromatic hydrocarbon pool in the catalysis of methanol conversion to light olefins on zeolite and zeotype materials through the usage of gas chromatography, mass spectrometry, and isotopic labeling. The goal was to identify and characterize the species responsible for the majority of ethylene produced in methanol-to-olefin catalysis. The mechanism for methanol to olefin catalysis was originally thought to only proceed through an aromatic hydrocarbon pool, but this was difficult to reconcile with product spectrums of different catalysts. From this developed a dual cycle mechanism consisting of two hydrocarbon pools.;Ethylene is the most valuable of the products produced from methanol to olefin catalysis. Modifying catalysts or reaction conditions to maximize ethylene selectivity requires an understanding of which hydrocarbon pool produces ethylene in the highest selectivity and just how selective that hydrocarbon pool is.;The first two chapters of this dissertation pertain to a general overview of zeolites, zeotypes, and the methanol to olefins reaction. An understanding of the methanol to olefins reaction and the catalysts that make it possible are necessary for the remaining two chapters. The latter two chapters focus on the aromatic hydrocarbon pool and its role in methanol to olefins catalysis. Chapter three focuses on determining the selectivity of the two most valuable products of methanol to olefin catalysis -- ethylene and propylene. This selectivity is determined for both the aromatic hydrocarbon pool and the olefinic hydrocarbon pool while minimizing the effects of the alternate hydrocarbon pool. In chapter four, the product spectrum of the reaction of several polymethylbenzenes are determined over a zeotype and zeolite that share the faujasite topology. Results confirm that methylated aromatic species are the best route to ethylene in methanol to olefins catalysis, and that a higher acid strength is more selective for ethylene.