Catalysis by Ultra Strong Acid Sitcs in Zeotite Crystals

对分子筛中强酸中心的形成、结构和催化作用进行了研究，得出以下结论：1.强酸中心的浓度取决于模板分子去除步骤的条件。在该步骤期间形成的氨和水影响形成步骤：因此，气氛和升温速率影响浓度。它由两个Al原子组成。催化活性随强酸性中心数量的增加而增加。2.进一步研究了氨水处理后HZSM-5上强酸性中心的形成。该位点由两个Al组成，一个Al在框架中，另一个在外表面上。在酸处理的HZSM-5分子筛上观察到一种很强的酸中心，它与酸处理的HZSM-5分子筛表面的酸中心相似，但表现出不同的性质。3.以NH_4Y为原料，经水蒸汽处理后，再经EDTA试剂处理，制得的超稳Y（UltraStable Y）具有较高的石蜡裂解活性。结果表明，高活性是由于β-沸石中形成了具有Bronsted酸性的桥连OH。4.β-沸石具有很强的酸性中心，由缺陷源Al和邻近的Si-OH组成。

Following conclusions were drawn on the formation, structure and catalysis of very strong acid sites in zeolite crystals.1.Concentration of the very strong acid site depends on the conditions of template molecule removal step. Ammonia and water formed during the step affects the step of formation : therefore, the atmosphere and ramp rate influences the concentration. It consists of two Al atoms. Catalytic activities increase with increasing the number of the very strong acid site.2.Furthermore, the formation of the site was studied on the HZSM-5 treated wills ammonia water. The site consists of two Al, one Al in the framework and another on the external surface. Very strong acid site, which appeared as a similar one but behaved in a different manner, was observed on the HZSM-5 treated with acids. TPD of ammonia however could not discriminate between them.3.USY (Ultra-stable Y) prepared from NH_4Y by steaming, and further treated with EDTA reagent has a high activity in the paraffin cracking. It was revealed that the high activity was due to the created bridged OH with the Bronsted acidity.4.β-zeolite has the very strong acid site, consistitig of the defect-origin Al and neighbor Si-OH.