H-ZSM-5-Catalyzed Hydroacylation Involved in the Coupling of Methanol and Formaldehyde to Aromatics

The selectivity of aromatics in methanol conversion over H-ZSM-5 zeolite is generally unsatisfactory because of the hydrogen transfer reaction which causes the simultaneous formation of alkanes. Here, we report an approximately 70% aromatics selectivity with lower olefins as primary byproducts in the coupling reaction of methanol and formaldehyde over H-ZSM-5 at 723 K and ambient pressure. Hydroacylation reactions catalyzed by H-ZSM-5 zeolite have been first discovered and confirmed during the coupling reaction. Besides Prins and aldol reactions, hydroacylation reactions also participate in the formation of aromatics. Moreover, the coupling mechanism including dienes and methyl-2-cyclopenten-1-ones intermediates is also proposed. This coupling reaction has the potential to be used in various applications.