不同脱铝深度稀土超稳Y沸石的催化性能的研究

STUDIES ON THE CATALYTIC PERFORMANCE OF REUSY WITH DIFFERENT DEGREES OF DEALUMINATION

本文选择正庚烷、正十六烷、环己烯和α-甲基萘作为探针分子考察了四种脱铝深度的稀土超稳Y沸石对短链烃、长链烃、单环烯烃和多环芳烃的催化性能,同时将催化性能与稀土超稳Y沸石的酸性关联起来。结果表明:四种沸石对各种探针分子的裂解活性依次为正十六烷>正庚烷>α-甲基萘>环己烯。对单个探针反应,除REUSY-38外,其余样品的裂解活性和选择性均与骨架铝有关而与非骨架铝无关;裂解活性随(N_(AI))_E的减少,酸强度的增加而增加,即REUSY-2>REUSY-2m>REUSY-1。反应温度的升高和脱铝深度的加深,都会导致探针反应的裂解深度的增加。

In order to study the catalytic performance of REUSY with different degrees of dealumination,n-heptane short chain paraffin,n-hexadecane long chain paraffin cyclohecene monocyclic olefin and α-methylnaphthalene polycyclic aromatics were chosen as the probe reactants. The results obtained were related to the acidic properties of REUSY measured by NH_3-TPD and IR. It is shown that on a given REUSY, the sequence of the activity for the cracking of probe reactants is n-hexadecane>nheptane>α-methylnaphthalene>cyclohexene and the acidic strength needed for these reactions is in the reverse order. For a given probe reaction, the cracking properties of different REUSY wers closely related to the framework Al and the acidic strength and not to the non-framework Al. The relationship between activity,selectivity and (N_(Al))_F has been shown and discussed.