L/MCM-41介微孔复合分子筛合成的影响因素  

Influence Factors of Synthesis of Meso-Micro-Porous Composite Molecular Sieve of L/MCM-41

作　　者：王春芳[1] 陈宜俍[1] 郭士岭[1] 张忠东[2] 高雄厚[2] 

机构地区：[1]郑州大学化工与能源学院,河南郑州450001 [2]中国石油天然气股份有限公司石油化工研究院,甘肃兰州730008

出　　处：《石油学报（石油加工）》2012年第1期50-54,共5页Acta Petrolei Sinica(Petroleum Processing Section)

基　　金：中国石油天然气股份有限公司沸石型高性能半再生重整催化剂的探索研究项目(09-YK-05-36)资助

摘　　要：以十六烷基三甲基溴化铵(CTAB)为模板剂,采用两步晶化法先合成L分子筛,再合成L/MCM-41复合分子筛,合成过程中采用了离子交换技术。用XRD、BET等测试手段对合成样品进行表征。考察了合成体系pH值、模板剂用量、晶化温度对合成产物的影响。结果表明,用硫酸调节合成体系pH值在10～11范围,以及n(CTAB)/n(SiO2)=0.25、120℃晶化2d的条件下,合成得到的L/MCM-41复合分子筛孔径比微孔分子筛大,为3.04nm;与水热晶化法合成的MCM-41相比,壁厚由0.55nm增大到1.81nm;水热稳定性也明显提高,在100℃沸腾状态下结构保持时间由原来的低于2h延长到8h。Meso-micro-porous L/MCM-41 composite molecular sieve was synthesized by two-step crystallization.The first step was to prepare zeolite L and the second step was to synthesize L/MCM-41 composite molecular sieve with cetyl trimethyl ammonium bromide（CTAB） as template and the technology of ion exchange.The products were characterized by X-ray diffraction（XRD） and BET.The effects of the synthesis conditions,including pH value,n（CTAB）/n（SiO2） and crystallizing temperature were studied.It was indicated that the optimal conditions of synthesis were as follows： pH value range of 10-11,n（CTAB）/n（SiO2）=0.25,crystallization temperature of 120℃,and crystallization time of 2 d,under which the pore diameter of the obtained L/MCM-41 composite molecular sieve was 3.04 nm,bigger than that of micro-porous molecular sieves.Compared with MCM-41 synthesized by ordinary hydrothermal method,the pore wall thickness of the obtained L/MCM-41 composite molecular sieve was raised from 0.55 nm to 1.81 nm,and the hydrothermal stability was better,that was,the meso-porous structure could keep unchanged for 8 h at 100℃,instead of 2 h.

关 键 词：离子交换 复合分子筛 介-微孔复合分子筛 L/MCM-41 

分 类 号：TQ17[化学工程—硅酸盐工业] TQ424.25