Yixiong Deng,Jiayu Zhou,Gen Li,Honghai Liu,Xionghou Gao,Yuanyuan Yue,Haiyan Li,Fangming Xie,Hongtao Liu
SBA-15 has recently emerged as a potential material for the catalytic conversion of large molecules. Usually, SBA-15 has a low content of aluminum due to the conventional acidic synthesis medium. Although a few approaches have been adopted to prepare Al–SBA-15 with a high alumina content, it is still challenging to prepare well-ordered Al–SBA-15 with a high alumina content. Here, we demonstrate a facile synthesis process in neutral mediums for the grafting of Al into the framework of SBA-15. This approach relies mainly on the dissociation of Si–O–Si bonds and the polymerization of Si–O–Si/Al bonds promoted by sodium persulfate (SPS) in neutral mediums. In this way, well-ordered Al–SBA-15 with a high aluminum content and enhanced acidity was obtained. Results of X-ray fluorescence spectroscopy (XRF) showed an n(SiO2)/n(Al2O3) ratio of 13.7, much lower than that of the conventional sample (21.7) obtained in acidic medium. The characterization results indicated the presence of a well-ordered Al-containing mesophase with high hydrothermal stability. Notably, the Al content and the acidity of Al–SBA-15 can be tuned by changing the SPS amount.
Butene plays an essential role in the area of petrochemical industry. The production of butene from the biomass-derived platform molecule γ-valerolactone (GVL) is of great interest. GVL decarboxylation reaction occurred under high temperature because the catalytic activity of the catalysts used before was not efficient for this reaction. In this work, beta zeolite with Si:Al = 5 was synthesized and used for GVL decarboxylation. It exhibited a higher catalytic performance than other commercial zeolites due to a large number of Lewis acid sites and relatively large micropore size. At 300 °C, 99.5% GVL conversion and 98% butene yield were obtained after condition optimizing. For further research, the influence of the Brønsted/Lewis acid ratio was investigated, and it turned out that Lewis acid was more active than Brønsted acid in crystalline material on GVL decarboxylation for the first time.