(259a) Selectivity and Shape Selectivity in Methanol to Hydrocarbons Conversion

Synthesis of energy carriers and petrochemicals from C1 feedstocks remains a formidable challenge with far-reaching implications of replacing current petrochemical feedstocks with alternative carbon-based sources such as natural gas, coal, and biomass. The dehydrative condensation of methanol-to-hydrocarbons occurs via an indirect hydrocarbon pool mechanism where methanol reacts with entrained olefinic or aromatic species in catalyst micropores initiating a sequence of steps leading to the formation of products and regeneration of the co-catalytic hydrocarbon pool species. This presentation will discuss the mechanistic elucidation of the dual olefin-arene methylation cycle and the rationalization for transients in product selectivity at early catalyst turnovers for methanol-to-olefins conversion over H-SAPO-34 via isotopic tracing experiments.