刘中民老师2005年3月的酸碱催化课课件.PPT

SAPO-34分子筛合成实例 解决的基础问题 Si 原子是如何进入分子筛骨架的 如何控制 Si 原子在分子筛骨架中的分布 XRD spectra of as-synthesized samples Crystallization curve of SAPO-34 IR results Assignment of the IR bands in framework vibration region of the as-synthesized samples 31P NMR of the gel samples in the first steps of the crystallization process The stirred mixing gel of the raw sources (silica sol, pseudoboehmite, orthophosphoric acid and water) The stirred mixing gel of a. and template (TEA). The b. gel after aging (the initial state of the crystallization). 27AlMAS(a), 31P MAS(b) and 29Si CP/MAS(c) NMR spectra of as-synthesized samples in the earlier stage of crystallization 27Al MAS NMR spectra of calcined and dehydrated samples in the earlier stage of crystallization Changes of the Al(IV), P(IV) and Si(IV) relative content (a) and relative proportion (b) of the as-synthesized samples with crystallization time 4.分子筛的基本性质 基本特点 多孔晶体，规整孔道结构 大比表面积 结构多样性 组成多样性 高热稳定性，水热稳定性 基本性质 离子交换性质 吸附性质 固体酸碱性质 5.分子筛的表征 XRD： 晶相，晶胞参数，晶体结构 电子显微镜：晶貌，组成 吸附－脱附：比表面积，孔径，孔容、 酸碱性等 红外光谱（IR)：－OH；酸碱性质；骨架；表面物种 NMR：结构微环境分析；酸碱性质 热重－差热：热稳定性，酸碱性，吸附（脱附）性质，积碳分析 XRD测定结晶度 一般测定8个主峰即可 也可用于测定杂晶相对结晶度 XRD测定Si/Al比 晶粒必须大于0.3微米 组成变化引起晶胞参数变化，XRD呈现规律性 可以测定Si/Al 判断晶体中是否有不均匀Al分布 IR法测定Si/Al 分子筛酸性的测定 酸碱中和（指示剂法） TPD IR 1H-NMR 31P-NMR TPD和IR最常用 H-MAS-NMR spectrum of HY zeolite IR spectra of HY zeolite without and with adsorbed pyridine Pyridine adsorption on different zeolites samples NH3-TPD of H-ZSM-5 1H 27Al MAS NMR of H-ZSM-5 Introducing the Players Sample Preparation Procedures Interactions Between Probe Molecules and Br?nsted Acid Sites 31P MAS NMR (TMP/H-ZSM-5/26) 31P MAS NMR (TMPO/H-ZSM-5) Correlation of Results Obtained from TMPO and TBPO 31P MAS NMR of Crystalline TBPO Acid Properties of H-ZSM-5 Determined by 31P MAS NMR in Conjunction with ICP 31P NMR Chemical Shift Assignments for Various Catalysts Adsorbed with TMPO and TBPO Distribution of Acid Sites for Various Catalysts 6.分子筛的催化性能 分子筛的特点 多孔晶体 孔道结构规整 Shape sel