摘要
采用表面润湿法,以微球硅胶为硅源,四乙基氢氧化铵为模板剂合成β沸石。系统地研究了投料n(SiO2)/n(Al2O3),n[N(C2H5)4OH]/n(SiO2),n(H2O)/n(SiO2),n(Na2O)/n(SiO2)对合成β沸石的影响,并对恒温和分段两种晶化方法进行了对比,得出了各种因素对合成β沸石的影响和最佳条件。结果表明,分段晶化法更有利于在较短的时间内合成高相对结晶度的β沸石;采用分段晶化法时,120℃下晶化8h就可形成足够的前驱物。无论采用恒温或是分段晶化,合成体系在150℃下的晶化时间应大于36h。通过对不同温度下晶化时间的控制有可能缩短合成β沸石的时间。
The synthesis of zeolite beta by surface-wetting method was studied using microspherical silica gel as silicon source and tetraethylammonium hydroxide as template. The influence factors such as the amount of template, ratios of SiO2/Al2O3, H2O/SiO2 and Na2O/SiO2 on the relative crystallinity of synthesized samples were investigated, and two crystallization routes, constant temperature and a two-step method, were compared to propose the optimum synthesis conditions. Test results illustrated that with two-step method crystallization under lower temperature （120℃） favored the formation of crystalline precursors, and adequate precursors were formed within 8-10 h; the growth of crystal could be accelerated by adjusting temperature to a higher degree （150℃）, and at least 36 h under 150℃ was needed for both methods. As compared with constant temperature crystallization, zeolite 13 synthesized by two-step crystallization method possessed higher crystallinity, and the total time of crystallization could be reduced as well.
出处
《石油炼制与化工》
CAS
CSCD
北大核心
2005年第6期9-13,共5页
Petroleum Processing and Petrochemicals
