微孔分子筛对催化合成3-甲基-6-叔丁基苯酚的影响研究

Study on the effects of microporous zeolites on the catalytic synthesis of 3-methyl-6-tert-butylphenol

目的对微孔分子筛催化合成3-甲基-6-叔丁基苯酚开展研究,探讨影响催化剂活性的主要因素,以期为工业化生产提供理论支撑。方法以HY,ReUSY,USY,LaY,ZMS-5,Hβ等微孔分子筛为催化剂进行性能评价,采用X射线衍射、场发射扫描电子显微镜、N 2物理吸附仪和化学吸附仪等表征方法对催化剂进行表征,并与催化剂活性数据进行关联。结果Y型、Hβ分子筛具有较好的催化活性,其中USY催化剂具有较好的转化率,最高达到68.6%,ZSM-5具有最优选择性,最高接近100%。结论催化剂的活性主要受比表面积、孔道结构、酸密度及酸强度等的影响,比表面积及孔道结构决定原料的转化率高低,酸密度及酸强度等影响目标产物的选择性,强酸位的存在会导致深度脱烷基化的发生。

Purposes—To discuss the main factors affecting the activity of catalysts with microporous zeolites as the catalysts for the synthesis of 3-methyl-6-tert-butylphenol in order to provide theoretical support for industrial production.Methods—The catalytic performance of HY,ReUSY,USY,LaY,ZMS-5,Hβand other microporous zeolites were comparatively investigated.The catalysts were characterized by X-ray diffraction(XRD),field emission scanning electron microscopy(SEM),N 2-adsorbtion,NH 3-TPD and chemisorption,and correlated with the catalytic performance of the catalysts.Result—Y-type and Hβzeolites showed good catalytic activities,among which USY catalyst had highest conversion,up to 68.6%,ZSM-5 had the highest selectivity,up to nearly 100%.Conclusion—The catalytic performance of zeolites for dealkylation is dependent on the specific surface area,pore structure,acid density and acid strength of these catalysts.The conversion rate mainly affected by the specific surface area and pore structure,and the selectivity mainly affected by the acid density and acid strength.Moreover,the strong acid sites will result in the excessively dealkylation.