原位晶化合成NaY复合材料过程中的多级孔道控制技术及介孔形成机理研究

Hierarchical zeolite material, novel zeolite with additional mesopore system besides the common micropore system, has advantages of zeolite (high thermal, hydrothermal stability and ordered microposity) and ordered mesoporous materials (large mesopore structure)simultaneity.At present,a systematic and deeply investigate is high needed to bring hierarchical zeolite material into practical applications since there are a lot of unsolved fundamental and technical questions in the synthesis and application of hierarchical zeolite material such as crystallization and mesopore formation mechanism of, control mesopore structure in and cost effective synthesis of hierarchical zeolite material.In this project, in order to overcome above motioned question in hierarchical zeolite synthesis, the new synthesis technology of hierarchical zeolite material with controllable hierarchical mesoporous by in-situ crystallization technology has been carried out. NaY zeolite composite material has been hydrothermally synthesized by in-situ crystallization using diatomite and kaolin. The effects of molar ratios of starting materials,crystallization temperatures and other factors on pore size distribution, pore structure, the relative crystallinity and the stability of porous materials have been particularly investigated.The best parameters and the basic rule of hydrothermally synthesized by in-situ crystallization have been achieved.On this basis, the new synthesis method of solid phase same seed crystal induction process has been provided.Controllability of the mesostructure during hydrothermally synthesized by in-situ crystallization with TPABr and without TPABr has been studied. A control technique of the mesostructure has been acquired.The changes of solid phase or liquid phase components were investigated at different crystallization times with all starting materials.The as-synthesized NaY zeolite composite material has been characterized by XRD, SEM, FT-IR, N2 adsorption-desorption and solid NMR. The formation mechanism of NaY zeolite composite material has been studied by a kinetic model. The formation mechanism of mesoporous and the crystallization mechanism of NaY zeolite composite material synthesized by in-situ crystallization technology using mixed clay have been provided. This project is high-level exploitation of kaolin and diatomite. The new technology will have an enormous influence on the in-situ crystallization technology. The new ideas will provide corresponding theoretical basis and method of developing originality novel product.

针对多级孔道沸石材料合成成本高及产品中介孔结构的可控性较差这一难点、热点问题，提出以混合粘土原位晶化合成多级孔道可控的NaY复合材料的新技术，并对反应机理及介孔形成机理做深入研究。项目以高岭土和硅藻土作为研究对象，详细研究原位晶化体系合成因素对多孔材料晶粒分布、孔结构、结晶度和稳定性的影响，获取最佳原位晶化参数和基本规律；提出固相同晶晶种诱导转化法合成多级孔道NaY沸石复合材料的方法；详细研究在模板及无模板存在条件下的孔道可控问题，获得一步水热法合成多级孔道NaY复合材料过程中孔道控制技术；结合XRD、SEM、红外和核磁等手段，提出原位晶化合成多级孔道的材料反应机理及介孔形成机理；对复合材料的催化性能进行研究。本项目为高岭土和硅藻土高层次的开发利用，提供的新技术对原位晶化技术的发展具有重大推进与革新影响力,提供的反应机理将为原创性产品开发提供相应理论依据和方法支持。

项目基于多级孔道沸石分子筛的合成成本过高，产品中介孔结构的可控性及介孔有序性较差这一难点、热点问题而提出的。项目主要针对混合粘土原位合成多级孔道沸石复合材料的体系开展了深入、系统的基础和应用基础研究，取得如下结果。.1、混合粘土物相的变化规律同单独粘土的变化规律相似，在高岭土:硅藻土=6:4和2:8的混兑比例下，其焙烧温度分别为950 ℃和900 ℃。在6:4的比例下最优水热合成配比为n(SiO2):n(Al2O3)=7.0，n(Na2O):n(SiO2)=0.45，n(H2O):n(Na2O)=30,合成NaY分子筛的相对结晶度为54.7%；在2:8的比例下最优配比为n(SiO2):n(Al2O3)=6.5，n(Na2O):n(SiO2)=0.5，n(H2O):n(Na2O)=55，合成的NaY分子筛的相对结晶度为56.3%。.2、微球加入凝胶后，合成产物在介孔范围内的孔容及比表面均有较大幅度的上升，介孔分布更为集中；当加入的凝胶比例为10％时，复合材料的孔结构达到最优，BET比表面积为480 m2/g，总孔容为0.41 ml/g，介孔孔容为0.22 ml/g。两段合成可有效的降低沸石分子筛的晶粒。在原位体系中引入化合物后，合成产物的结晶度出现下降趋势，无机物引入后下降的幅度低于有机物和高分子物质。合成产物的孔径增大，无机物增加的幅度明显低于有机物和高分子物质。合成产的晶粒降低，有调整孔道结构的作用，有机物和高分子物质对孔道结构调整的幅度较大，呈现多级孔道分布。.3、混合粘土原位合成多级孔道复合材料的体系是自发成核体系，成核活化能为49.39 KJ/mol，晶体生长活化能为33.59 KJ/mol。.4、采用新材料开发出的催化剂和助剂是一种能够显著提高汽油收率的产品，与对比剂相比，塔底油转化能力强，汽油产率提高1%以上，辛烷值提高0.5个单位以上。.项目提供的新技术在水热原位合成技术领域里有重大突破性进展，提供的新材料成功应用于制备FCC催化剂和助剂，提供的新思路为更深化的原创性产品开发提供理论依据和方法支持，形成原创的领先技术。项目执行期间，发表学术论文13篇，期刊论文10篇，会议论文3篇，其中SCI收录的论文4篇，EI收录的论文6篇。获得中国石油与化工联合会科技进步奖三等奖。获得授权中国发明专利7件，申请中国发明专利7件。