Deng Yixiong, Zhou Jiayu, Li Gen, Liu Honghai, Gao Xionghou, Yue Yuanyuan, Li Haiyan, Xie Fangming, Liu Hongtao
State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, P. R. China.
China Petroleum Technology and Development Corporation, Beijing 100027, P. R. China.
Inorg Chem. 2022 Aug 1;61(30):11820-11829. doi: 10.1021/acs.inorgchem.2c01571. Epub 2022 Jul 15.
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 AlSBA-15 with a high aluminum content and enhanced acidity was obtained. Results of X-ray fluorescence spectroscopy (XRF) showed an (SiO)/(AlO) 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 AlSBA-15 can be tuned by changing the SPS amount.
SBA - 15最近已成为一种用于大分子催化转化的潜在材料。通常，由于传统的酸性合成介质，SBA - 15的铝含量较低。尽管已经采用了一些方法来制备高氧化铝含量的Al - SBA - 15，但制备具有高氧化铝含量的有序Al - SBA - 15仍然具有挑战性。在此，我们展示了一种在中性介质中进行的简便合成过程，用于将铝接枝到SBA - 15的骨架中。这种方法主要依赖于中性介质中过硫酸钠（SPS）促进的Si - O - Si键的解离和Si - O - Si/Al键的聚合。通过这种方式，获得了具有高铝含量和增强酸度的有序AlSBA - 15。X射线荧光光谱（XRF）结果显示（SiO）/（AlO）比为13.7，远低于在酸性介质中获得的传统样品（21.7）。表征结果表明存在具有高水热稳定性的有序含铝中间相。值得注意的是，AlSBA - 15的铝含量和酸度可以通过改变SPS的量来调节。
