摘要
采用降解法制备Al-Z-SBA-15复合分子筛,利用XRD、FT-IR等方法对Al-Z-SBA-15的理化性质进行了表征分析。结果表明,沸石结构单元以五元环的形式存在于骨架中;大部分铝以稳定的骨架铝的形式嵌入到孔壁,提高了孔壁结晶度。通过X射线粉末衍射(XRD)、N2吸附-脱附等分析手段研究了铝物种与沸石结构单元对介孔分子筛Al-Z-SBA-15水热稳定性的影响。结果表明,沸石结构单元和Al^(3+)的引入显著提高了分子筛Al-Z-SBA-15的水热稳定性,提高了硅羟基的缩合度和孔壁的厚度;Al^(3+)水解能力较强,在水热环境中形成的羟基水合配离子与Si—OH脱羟基形成Al—O—Si,使Al^(3+)禁锢在介孔表面,对骨架硅起到保护作用。经100℃沸水处理432h和600℃100%水蒸气处理10h后,Al-Z-SBA-15仍保留介孔结构。
The composite molecular sieves of Al-Z-SBA-15 were synthesized by using a zeolite-dissolving method.The sample was characterized by means of XRD,FT-IR.The results showed that the units of zeolit was an Al-Z-SBA-15 mesoporous material with Al—O—Si pore walls.Most of the Al was incorporated into the framework of Al-Z-SBA-15,and it improved the crystallinity of the pore walls.The effects of Al^3＋and the zeolite structure modification on the hydrothermal stability of Al-Z-SBA-15 mesoporous molecular sieves were studied by XRD、N2adsorption-desorption.The results showed that the introduction of zeolite structure unit and Al^3＋improved the hydrothermal stability of the molecular sieve Al-Z-SBA-15 significantly,and improved the polymerization degree of the Si—OH and the pore wall thickness.Al^3＋hydrolysis ability was strong,and hydrated hydroxy complex ion formed Al—O—Si with Si—OH through dehydroxylation in a hydrothermal environment.Therefore Al 3＋was detained in mesoporous surface,this could protect framework silicon.Al-Z-SBA-15 still retained mesoporous structure after 100 ℃ boiling water treatment 432 hand 600 ℃100% steam treatment 10 h.
出处
《精细石油化工》
CAS
CSCD
北大核心
2016年第3期1-6,共6页
Speciality Petrochemicals
