基于表面/界面作用调控的高性能负载型固体碱催化剂的设计

This project will mainly focuse on the design and preparation of a series of novel supported solid base catalysts through surface/interface control. A varity of solid base catalysts will be obtained by introducing different basic compounds (functional groups) on the surface of support materials, like porous carbon, silica and alumina. The surface/interface interaction between the support and basic centers will be adjusted by changing preparation parameters, which can finally infulence the basicity of the supported base catalysts. Various characterization means will be carried out to investigate the nature of surface/interface interaction, and its infulence on the basic property of the supported solid base catalysts. The catalytic performance of these solid base materials will be investigated for some significant reactions, such as transesterification of triglycerides with methanol, aldol condensation of methyl acetate with formaldehyde. Efforts will be mainly drawn on studying the effect of catalyst basicity on their catalytic activity, selectivity and stablity. The effect of other factors, such as functional groups (including acidic sites) existed on the surface of solid base catalysts, will be also investigated. Moreover, the relationship between the surface properties of the catalysts and their catalytic performances will be built, and the catalytic reaction mechanism will be also discussed. We believe that this work will be beneficial to the design and development of highly efficient supported solid base materials for catalytic application.

本项目拟开展基于表面/界面作用调控的高性能负载型固体碱催化剂的设计工作。主要以多孔炭、氧化硅及氧化铝为载体，采用浸渍法、沉积沉淀等方法引入不同种类碱性化合物（基团）,制备各种负载型固体碱催化剂。将根据载体结构和表面性质，通过改变制备参数，系统调节碱性基团-载体间表面/界面相互作用，继而实现对固体碱催化剂活性中心结构和性质的有效调控。结合多种表征手段研究表面/界面作用的本质及其对催化剂碱中心结构和性质的影响规律。通过具有重要研究意义的酯交换、甲醛与羧酸（酯）缩合等反应考察固体碱催化剂的性能，研究碱中心性质变化对催化剂活性、选择性及稳定性的影响。还将重点考察固体碱催化剂表面存在的酸中心和其它基团对催化反应的促进作用，逐步建立催化剂活性中心结构性质和反应性能之间的关系，阐明催化作用机制。本项目的实施将能为新型高效固体碱催化剂的设计与制备提供更多的理论依据。

设计制备性能优异的固体碱催化剂具有重要的科学意义。本项目通过调节碱性基团-载体间的表面/界面相互作用，构筑出系列多功能复合固体碱催化剂；考察了催化剂对甲苯-甲醇侧链烷基化等反应的催化性能；探讨了催化剂活性中心性质等基础科学问题，取得的代表性研究成果如下：.采用不同助剂对离子交换法制备的CsX催化剂进行修饰，得到几类性能较为优异甲苯-甲醇侧链烷基化催化剂。引入适量助剂如BPO4能够有效覆盖催化剂表面部分强碱中心，同时会引入适量弱酸中心，从而有效抑制双齿甲酸盐的生成，提高甲醇的利用率和苯乙烯的收率。以SBA-15为载体制备的Cs基催化剂对乙酸甲酯与甲醛气相缩合制丙烯酸甲酯反应表现出优异性能，弱碱性的Cs-O-Si物种为主要的活性中心。.采用溶胶-凝胶法制备的氮掺杂多孔炭材料NC对水体系中硫化钠还原硝基苯的反应表现出良好的催化活性和稳定性。在室温下，NC就可以有效催化还原硝基苯为苯胺，性能明显优于文献中报道的其它炭材料催化剂。NC材料表面的碱性基团如吡啶氮和季氮是催化剂的主要活性中心。氮摻杂炭材料优异的催化活性和结构稳定性使其在水体系修复方面具有潜在应用前景。.以氨丙基修饰的ZrSBA-15为载体制备的PtPd双金属纳米粒子催化剂能有效催化氨硼烷分解制氢和对硝基苯酚加氢的串联反应。有机胺的存在有利于纳米粒子的高度分散，双金属组分间协同作用和金属-载体间界面协同是催化剂性能提升的关键因素；以球滴法制备的毫米级聚丙烯腈小球为载体制备的Pd基复合纳米粒子催化剂对甲酸分解制氢反应表现出优异的性能。载体上的氰基基团能提供合适的碱性环境促进甲酸分子的吸附活化，从而显著提升催化剂的性能。.相关成果已在Catal. Sci. Technol., J. Phys. Chem. C等刊物上发表SCI论文20余篇，申请发明专利1项。所取得的成果能够为新型固体碱催化剂的设计及开发提供理论参考依据。