摘要
梯度孔分子筛是一种具有强酸中心和良好热稳定性、水热稳定性的多级孔道结构的分子筛。重点介绍了模板法合成梯度孔分子筛的研究进展,包括硬模板法和超分子模板法等,并阐述了梯度孔的形成机制。硬模板法的梯度孔形成机制是除去占据分子筛空间的硬模板形成梯度孔;超分子模板法的梯度孔形成机制是除去与分子筛发生作用或组装的表面活性剂(或有机大分子模板)形成梯度孔。结合实例阐述了梯度孔分子筛在石油化工及有机大分子催化方面的应用,梯度孔分子筛能通过优化传质过程、改善催化剂的活性和选择性来提高催化效率。
Hierarchical zeolite crystal is a porous mesopores. The kind of materials with hierarchical bi-or material with micropores and intracrystalline trimodal pore size distributions inherits strong acid sites and excellent thermal/hydrothermal stability. The intracrystalline mesopores can accelerate the transition of reactants and the diffusion of products so that the selectivity and activity of the catalysts were enhanced in the catalytic reaction involving large molecules. Hierarchical pore zeolite crystals were synthesized by templating methods, mainly including solid templating and supramolecular templating. The mechanism of hierarchical pore formation in solid templating is that the zeolite crystal is in intimate contact with a solid material that is being removed to produce the mesopores. Similarly, the mechanism of hierarchical pore formation in supramolecular templating is that the zeolite crystal is in direct contact with a supramolecular assembly in organized surfactants or organic molecules, which is removed to generate the mesopores. Finally, this paper explains the potential of hierarchical pore zeolite crystals combined with several cases in the petroleum chemical industry and the large molecule catalytic applications.
出处
《石油化工》
CAS
CSCD
北大核心
2011年第1期100-110,共11页
Petrochemical Technology
基金
国家重点基础研究发展计划项目(2010CB226905)
山东省自然科学基金项目(Y2007B35
Y2008B58)
关键词
梯度孔分子筛
模板剂
酸催化
hierarchical porous zeolite
template
acid catalysis
