碱酸改性处理方案对介孔β沸石孔分布和织构性质的影响  

Effects of Alkali and Acid Modification Treatments Method on Size Distribution and Textural Property of β Zeolites

作　　者：王亮[1] 肖长春[1] 刘金环[1] 张舒冬[2] 封瑞江[1] 金英杰[1] 

机构地区：[1]辽宁石油化工大学化学化工与环境学部,辽宁抚顺113001 [2]中国石化抚顺石油化工研究院,辽宁抚顺113001

出　　处：《石油化工》2015年第7期839-845,共7页Petrochemical Technology

基　　金：辽宁省自然科学基金项目(200922180);国家自然科学基金项目(21171083)

摘　　要：采用水热碱蚀-碱溶滤-酸洗逐级处理方法对Hβ沸石进行介孔改性研究。借助XRD、N2吸附-脱附、SEM、TEM等技术考察了改性方法对改性沸石的介孔形成、介孔孔分布和织构性质的影响;建立了半经验粒内介孔体积分率模型,分析了织构介孔在基质结晶性和体积构成上的差异。实验结果表明,改性沸石具有较高的比表面积和介孔率及倾向于均一化的介孔分布。水热碱蚀导致介孔孔分布趋于均一化;碱溶滤脱硅是沸石产生介孔的关键步骤;酸洗脱铝具有拓孔作用。当Na OH溶液浓度由0.1 mol/L增至0.3 mol/L时,经水热碱蚀-碱溶滤-酸洗-铵交换处理得到的改性沸石的粒内介孔体积比率均保持在70%以上。The mesoporous modification of Hβ zeolite（n（Si）∶n（Al）=18.7） was carried out by a sequential scheme,namely hydrothermal alkali pre-etching,bulk alkali leaching and acid washing. The effects of the modification on the mesoporous formation,pore size distribution and textural properties of the zeolite were investigated by means of powder XRD,N2 adsorption-desorption,SEM and TEM. A semi-empirical model for calculating the volume fraction of the intraparticle mesopores was established. It was confirmed that the Hβ zeolites treated with alkaline and acid had bigger specific surface area,higher mesoporosity and uniform mesopore size distribution. In the modification,the hydrothermal alkali pre-etching promoted the uniform mesopore size distribution,the alkali leaching for desilication played a crucial role in the mesopore formation,and acid washing for dealumination led to the increase of the mesopore size. Based on the calculated results,the volume fraction of the intraparticle mesopores reached more than 70% when the concentration of Na OH solution changed in the range of 0.1–0.3 mol/L.

关 键 词：介孔β沸石 碱酸处理 介孔分布 介孔体积模型 

分 类 号：TQ424.25[化学工程]