硅源对小晶粒ZSM-5分子筛性质及其甲醇转化制丙烯催化性能的影响

Effect of Silica Sources on the Properties of ZSM-5 and Their Catalytic Performance for Methanol Conversion to Propylene

固定晶化条件和合成原料参数,分别以四丙基氢氧化铵和偏铝酸钠为模板剂和铝源,考察了硅源类型(正硅酸乙酯、硅溶胶、硅酸钠、硅酸和白炭黑)对合成ZSM-5分子筛理化性能的影响。结果表明,产物的相对结晶度和产率按白炭黑、硅酸、硅酸钠、硅溶胶和正硅酸乙酯顺序依次减小;比表面积按硅酸、正硅酸乙酯、白炭黑、硅溶胶和硅酸钠顺序依次减小,且以硅溶胶合成的ZSM-5分子筛的总孔容最大,而微孔孔容最小;甲醇转化制丙烯的催化性能按硅酸、正硅酸乙酯、硅溶胶、硅酸钠和白炭黑顺序依次减小。

With fixed crystallization conditions and synthetic raw material parameters, we used tetrapropyl ammonium hydroxide and sodium aluminate as the template and aluminum source respectively, and then the effect of silica sources （TEOS（ethyl silicate）,silica sol, sodium silicate, silica acid and white carbon black） on the physical and chemical properties of ZSM-5 zeolite was investigated. Results show that the relative crystallinity and production yield were in decreasing order for silica sources from white carbon black, silica acid, sodium silicate, silica sol, to TEOS, and the specific surface area was in decreasing order for silica sources from silica acid, TEOS, white carbon black, silica sol, to sodium silicate. Furthermore, among all cases tested, the total pore volume of ZSM-5 synthesized by silicon sol is the largest, while the micropore volume is the smallest. In addition, the catalyst performance of CH3OH conversion was in decreasing order for silica sources from silica acid, TEOS, silicon sol,sodium silicate, to white carbon black.