Enhanced propene/ethene selectivity for methanol conversion over pure silica zeolite: Role of hydrogen-bonded silanol groups

• Pure silica ZSM-11 gives a three times higher P/E ratio than H-ZSM-11 (Si/Al = 26).
• H-bonded silanol groups are active sites in pure silica ZSM-11.
• H-bonded silanol groups favored the formation of propene and butene.
• Hydrogen transfer reactivity is determined by different acid sites.

Pure silica zeolite with MEL structure (Si-ZSM-11) was firstly reported as an efficient Methanol-to-Propene (MTP) catalyst in methanol conversion, with higher propene yield (14.0 wt.%) and propene/ethene ratio (5.9) than H-ZSM-11 zeolite with a Si/Al ratio of 26 (7.4 wt.% and 1.9, respectively). Hydrogen-bonded silanol groups in Si-ZSM-11 are weakly acidic and act as active sites in methanol conversion, predominantly promoting propene production and inhibiting side reactions.

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