Sucrose is an abundant, cheap and sustainable substrate for producing high value-added chemicals. In this work, the role of weak Brønsted (B) acid site of Sn-β zeolite was revealed in sucrose conversion to methyl lactate (MLA). Sn-β zeolites were prepared by post-synthesis and hydrothermal synthesis in F ‒ media and modified by Mg 2+ to tune the B acidity. The acidity of the zeolites was characterized by FT-IR spectroscopy of pyridine/CD 3 CN adsorption and hydroxyl region. Their catalytic performance for sucrose conversion to MLA in methanol indicates that weak B acid sites of silanols are indispensible for breaking the glycosidic bond of sucrose, so the highest MLA yield was obtained over the postsynthesized Mg-Sn-β-P with moderate amount of weak B acid sites of silanols, strong L acid sites and no strong B acid sites, which juggled the alcoholysis/hydrolysis of sucrose and the retro-aldol of C 6 monosaccharide to MLA, and at the same time inhibited the dehydration side-reaction.
Efficient conversion of ethyl levulinate (EL) in high concentration to γ-valerolactone (GVL) at moderate temperature via catalytic transfer hydrogenation strategy is highly desirable. In this work, hydrothermally synthesized Sn-β zeolite with high Sn content was employed as a catalyst to realize this aim. Fully crystallized Sn-β zeolite with high Sn content ( n Si / n Sn = 60) was successfully synthesized within 12 days using MgCl 2 as a promoter. The synthesized zeolites were characterized by XRD, SEM, UV-vis spectroscopy, FT-IR spectroscopy and XPS. The L acid density of Mg-Sn-β-60-12d increased to 90 μmol g −1 compared to Mg-Sn-β-100-7d (56 μmol g −1 ). 92% yield of GVL was achieved on Mg-Sn-β-60-12d using high concentration of EL (1.2 mol L –1 ) as reactant at 130 o C for 8 h. The performance of Mg-Sn-β is better than that of Sn-β with same n Si / n Sn . The reaction mechanism over Mg-Sn-β was discussed. In addition, Mg-Sn-β-60-12d showed excellent stability and reusability during five runs.
危险品化学品经营许可证（带存储）