Zeolites Y from organic-free system with adjustable Si/Al ratios (2.15–2.87) were synthesized and compared to the commercial zeolite Y (HSZ-320NAA, Tosoh Co., Japan). We found that the as-synthesized and commercial zeolites with similar X-ray crystallinity and Si/Al ratios tend to show different susceptibility to removal of framework aluminium. Furthermore, our study indicates that increased extraction of framework aluminium atoms not always result in lower crystallinity. We attribute this behaviour to different distribution of Si(nAl) building units and structural defects as revealed by ²⁹Si MAS-NMR, ²⁷Al MAS-NMR and powder XRD analyses. We also found that the progressively increasing amount of extra-framework aluminium is inversely related with the Si/Al ratios of the dealuminated samples and contributes to higher catalytic activity. Finally, we evaluated the influence of X-ray crystallinity and Si/Al ratios on the catalytic performance of the as-synthesized and commercial samples.

合成了具有可调节的Si / Al比（2.15-2.87）的无有机体系的Y沸石，并将其与商业化的Y沸石（HSZ-320NAA，Tosoh Co.，日本）进行了比较。我们发现，具有相似的X射线结晶度和Si / Al比的合成沸石和商品沸石倾向于显示出不同的去除骨架铝的敏感性。此外，我们的研究表明，增加骨架铝原子的提取并不总是导致较低的结晶度。我们将此行为归因于Si（nAl）建筑单元的不同分布和结构缺陷，如²⁹ Si MAS-NMR [ ^27]所揭示。Al MAS-NMR和粉末XRD分析。我们还发现，逐渐增加的骨架外铝的量与脱铝样品的Si / Al比成反比，并有助于更高的催化活性。最后，我们评估了X射线结晶度和Si / Al比对合成样品和商业样品催化性能的影响。