Does crystallite size dominate MTP performance over Silicalite-1 zeolite in methanol to propene?

The relations of crystallite sizes over Silicalite-1 zeolite with the silanols distribution and catalytic performance in methanol to propene (MTP) reaction were determined. The catalytic lifetime and the formation of ethene was independent of the crystallite size, but was attributed to the silanols distribution. The internal isolated silanol groups (I) affects the diffusion restrictions of intermediate species. The external isolated silanols (E) determined the tolerance for coke capacity on the external surface. Propene and the initial catalytic activity was dominated by the amount of Brønsted acid sites. [Display omitted] •Silicalite-1 zeolites with various crystallite size and silylation treatments were prepared.•Product distribution and deactivation behaviors were independent of crystallite size.•H-bonded silanols were responsible for the initial catalytic activity and propene yield.•Distribution of isolated silanols was decisive for the deactivation and ethene production.