铝修饰改性对SBA-15分子筛性质及催化剂性能的影响

Influences of Al modification on the properties and catalytic performance of SBA-15 molecular sieves in hydrocracking

摘要: 分别采用调变pH值合成法和后处理嫁接法制备了铝修饰改性的SBA-15分子筛，通过XRD、Al核磁、N₂吸附脱附、NH₃-TPD等方法对改性分子筛的理化性质进行了分析表征，考察了不同的Al修饰改性方法对分子筛性质和加氢裂化催化剂性能的影响。结果表明，调变pH值合成法能够有效地对SBA-15进行Al改性，得到的Al-SBA-15分子筛具有高度有序的六方孔道结构，较好的水热稳定性。Al的引入提高了SBA-15的表面酸性，并使其在加氢裂化反应中表现出较好的中油选择性。

Abstract: SBA-15 molecular sieves were modified with Al by adjusting pH value and post-grafting synthesis and used as the catalysts for hydrocracking. The new mesoporous materials were characterized by XRD, ²⁷Al NMR, N₂ adsorption and desorption and NH₃-TPD. The results showed that Al-SBA-15 is successfully obtained through synthesis via adjusting pH value; it exhibits an ordered hexagonal mesoporous structure and well hydrothermal stability. Al modification is able to enhance the amount of surface acid sites of SBA-15, which induces the Al-SBA-15 catalyst with high selectivity to middle distillate for hydrocracking.