介孔AlPO_4分子筛前驱体的原位焙烧  

In situ calcinations of the precursor of mesostructural aluminophosphate molecular sieves

作　　者：任海伦[1] 辛峰[1] 

机构地区：[1]天津大学化工学院,天津300072

出　　处：《材料热处理学报》2006年第3期41-44,共4页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金(20376056)

摘　　要：采用热重(TGA)-差热(DTA)、原位X射线衍射(XRD)、原位红外光谱(FT-IR)和扫描电镜(SEM),对介孔AlPO4分子筛前驱体焙烧过程中的多种变化进行实验研究。TGA-DTA和原位FT-IR结果表明,前驱体脱除主要分为两步:模版剂中N—H键首先断裂,然后甲基(CH3)和亚甲基(CH2)被氧化除去;从原位XRD分析结果可以看出,焙烧过程受温度的影响表现为结晶度的变化,当焙烧温度超过650℃时,AlPO4分子筛会转化成磷石英相和无定形相;SEM照片清楚表明,焙烧使无定型的前驱体转化成柱状分子筛。另外升温速率高于10℃.min-1,会造成分子筛颗粒破碎。By calcinating the precursor of AlPO4 to remove the template, A1PO4 molecular sieves was prepared and investigated by in situ X-ray diffraction (XRD), thermogravimetry-differential thermal analysis (TGA-DTA), Fourier transformation infrared spectrometer (FT-IR) analysis and scanning electron microscopy (SEM). The results of TGA-DTA and the in situ FTIR show the removal of precursor involves two steps. First, the N-H in the template is decomposited, and then the CH2 and CH3 are removal by oxidation. The results of in situ XRD at different temperatures indicate that the crystallinity of the products changes as the calcinating temperature increases and the mesostructural A1PO4 can transform into tridymite dense phase and an amorphous phase above 650°C. The observation of SEM indicates that amorphous precursor transforms into pillar molecular sieves in the process of calcination, in addition, high heating rate can lead to cracking of the pillar molecular sieves particles.

关 键 词：焙烧 前驱体 原位 介孔AlPO4 分子筛 

分 类 号：O614[理学—无机化学]