摘要:研究了酸处理过程对Beta分子筛Bronsted酸和Lewis酸分布及其作为载体催化十氢萘加氢开环反应的影响。采用XRD、BET、XRF、Py—FTIR等表征了不同浓度盐酸处理的分子筛,结果表明,酸处理后Beta分子筛结晶度及孔径无明显变化,比表面积先增加后降低。随盐酸浓度的增加,n(SiO2)/n(Al2O3)增大,总酸量逐渐降低;在盐酸浓度大于0.1mol/L时,酸处理主要改变了分子筛的B酸位。十氢萘加氢开环反应实验结果表明,B酸位对Beta分子筛催化十氢萘开环反应影响较大,酸性越强越易导致作为载体的Beta分子筛失活。0.1mol/L盐酸处理得到的催化剂酸性适宜,比表面积最大,活性及开环异构产物的产率最高。
This paper mainly explored the influence of acid treatment on the Bronsted and Lewis acid distribution of Beta zeolites and their catalytic activity for the selective ring opening of decalin. The Beta zeolites treated by different concentration of hydroehloric acid were characterized by XRD, BET, XRF and Py-FTIR. The crystallinity and pore size had no obvious change after acid treatment. The speeific surface area of the HC1 treated zeolites increased first and then decreased as the concentration of hydrochloric acid increased. Meanwhile, the ratio of SiO2/A1203 increased and the total acid content gradually de- creased with the increase of the concentration of hydrochloric acid. The Bronsted acid site was mainly modified by the acid treatment as the acid concentration was higher than 0. 1 mol/L. The results of activity experiments showed that the Bronsted acid sites played a dominant role in the ring opening of decalin. Higher Bronsted acid sites easily led to deactivation. The catalyst treated by 0. 1 mol/L HC1 solution exhibited optimum activity owing to its suitable acid sites and high surface area.