The present work reports an easy and low-cost way of industrial relevance for post-synthetic upgrading of zeolite Y, achieved by the rational application of chemical induced framework defects to engineering zeolite mesoporosity. Si-defects and Al-defects, formed as a result of the selective removal of framework Si and Al atoms by alkaline treatment and oxalic acid leaching, respectively, are introduced into the framework of an as-synthesized zeolite Y. Such defect-containing zeolites were ion-exchanged, steamed and acid washed, and the final products were subjected to a comprehensive physico-chemical characterization. The results show that Al-defects, due to its inclination to condensation during the heating stage before steaming, hamper the migration and coalescence of steaming induced framework defects, hence suppressing the propagation of mesoporosity during steaming. In contrast, the presence of Si-defects favors the formation of mesoporosity in zeolite Y framework during dealumination. Further, we demonstrate that the introduction of Si-defects can be incorporated into the zeolite synthesis process without compromising the ability to enhance zeolite mesoporosity. The derived catalysts show higher gasoline selectivity than the base catalysts in the catalytic cracking of a wax oil from Daqing.

本工作报告了一种通过合成化学诱导的骨架缺陷合理地应用到工程沸石介孔率中来实现沸石Y合成后升级的简便，低成本的产业相关性方法。分别通过碱处理和草酸浸出选择性去除骨架Si和Al原子而形成的Si缺陷和Al缺陷被引入到合成沸石Y的骨架中。这种含缺陷的沸石进行离子交换，蒸煮和酸洗，然后对最终产物进行全面的物理化学表征。结果表明，由于铝缺陷在汽蒸之前的加热阶段倾向于凝结，因此阻碍了汽蒸引起的骨架缺陷的迁移和聚结，因此抑制了在蒸煮过程中介孔的传播。相反，硅缺陷的存在有利于在脱铝过程中在沸石Y骨架中形成介孔性。此外，我们证明可以将Si缺陷的引入并入沸石合成过程中，而不会损害增强沸石介孔性的能力。在来自大庆的蜡油的催化裂化中，衍生的催化剂显示出比基础催化剂更高的汽油选择性。