A scanning pulse reaction technique for transient analysis of the methanol-to-hydrocarbons reaction

A method of scanning pulse gas chromatography (SP-GC) suitable for time-resolved analysis of transient response of catalysts to reactant pulses is introduced. Applied to the methanol-to-hydrocarbons reaction over several zeolite-based catalysts (HZSM-5, Ca/ZSM-5 and Ga/ZSM-5), SP-GC provided quantitative information about the transient reactivity and selectivity during methanol conversion. The SP-GC analysis demonstrates substantial differences in the relative rates of hydrocarbon formation between catalysts that favor aromatic or olefin cycles of the dual cycle hydrocarbon pool mechanism. The influence of metal promoters on the main reaction pathways was highlighted with an emphasis on mechanistic aspects.

Automated summary

This paper introduces a scanning pulse gas chromatography (SP-GC) method suitable for analyzing the transient response of catalysts to reactant pulses. Applied to methanol-to-hydrocarbons reaction over various zeolite-based catalysts, SP-GC provides quantitative information about the transient reactivity and selectivity. The analysis demonstrates differences in the relative rates of hydrocarbon formation between catalysts favoring aromatic or olefin cycles of the dual-cycle hydrocarbon pool mechanism. The influence of metal promoters on the main reaction pathways is highlighted, with a focus on mechanistic aspects.