Synthesis of Sn-Beta Zeolite via Quasi-Solid-Phase Route with Low Amount of Organic Template

Graphical Sn-Beta was synthesized by a quasi-solid-phase method without adding additional solvent. Low amount of template and mineralizer was used as compared with traditional route. Sn-Beta zeolites were successfully synthesized through a quasi-solid-phase method by grinding the raw materials and then crystallizing in solid state. The method employed small amount of tetraethyl ammonium hydroxide (TEAOH) and no additional solvent, except for the water contained in template solution. The synthesis conditions including amount of TEAOH and water, and crystallization time were explored. Under optimized conditions, the obtained sample showed high crystallinity and capped square bipyramidal crystals. The diffuse reflectance ultraviolet-visible spectra and Fourier transform infrared spectra of CD 3 CN and pyridine adsorption were used to characterize the state of Sn and acidity in Sn-Beta sample. Sn 4+ ions were introduced into the framework which generated strong Lewis acid sites. The sample synthesized by quasi-solid-phase method gave 38.5 % methyl lactate (MLA) yield for the conversion of glucose to MLA, which is comparable to that of Sn-Beta prepared with conventional hydrothermal method (39.4 %).