Mechanistic Insights in the Methanol-to-Hydrocarbon Process Using Advanced and Combined Operando Spectroscopy

摘要

Chemistry and Catalysis, Utrecht University, Utrecht, Netherlands The Methanol-to-Hydrocarbon (MTH) process is currently of great interest as the feedstocks for the production of methanol can be obtained from practically any carbon source. Thereby, an alternative route for the production of more renewable plastics and fuels can be obtained. The MTH process, in which methanol is converted to hydrocarbons, can be catalyzed by zeolites. The amount of Bronsted acid sites, the pore size and structure and the cage size and structure of the zeolites determine which actual products are formed.1,2 The most accepted mechanism of the formation of hydrocarbons within the structures is the hydrocarbon pool mechanism or the dual cycle mechanism, in which aromatic hydrocarbons and olefins function as intermediate products in the zeolite cages. Insights in the formation of these intermediates during the conversion of methanol are required to define the actual mechanism and to gain more knowledge about the tunability of the process within the frameworks of the zeolites. Additionally, the formation of large hydrocarbon species as polyaromatic compounds can block the pores as they occupy the whole cavity opening or large coke species can accumulate on the outside of the zeolites by which the accessibility of the pores and cavities is hindered. In the recent years, our group developed multiple operando spectroscopic techniques to analyze the formation of different species within the cages of the zeolites during the MTH reaction to, in the end, follow the active and deactivating period of the process.