Dry Gel Conversion Method for the Synthesis of Organic–Inorganic Hybrid MOR Zeolites with Modifiable Catalytic Activities

Dry gel conversion (DGC) technique is first applied in the synthesis of organic–inorganic hybrid aluminosilicate zeolites. By using the DGC method, methylene-bridged organic–inorganic hybrid zeolites with an MOR topology are synthesized without organic additive, which are structurally characterized by powder XRD, FTIR, solid-state 29Si, 13C, 27Al MAS NMR, SEM, elemental analysis, XRF, XPS, and N2 adsorption techniques. This work first reports that thus-synthesized methylene-bridged hybrid zeolites can be successfully bestowed with excellent catalytic activities through different modification treatments. Co2+-exchanged hybrid zeolites are applied in the epoxidation of alkenes with air to achieve good conversions and selectivities. Especially, methylene-bridged hybrid zeolites can be sulfonated with fuming sulfuric acid to form acidic MOR-SO3H catalyst, which exhibits highly catalytic activity for the acid-catalyzed condensation reaction of cyclohexanone and glycol. This method will be one potential route for the fabrication of organic–inorganic hybrid zeolite or related molecular sieve catalysts.