新型介孔聚合物基疏水固体酸的设计与合成及其在催化生物质转化中的应用研究

It colud be said that acid catalysts involves the largest amounts of catalysts used and the largest economical effort in the oil refining and fine chemical industry.Up to now, the replacement of mineral liquid acids by solid acids for the production of fine chemicals has been paid much attention due to the advantages of easy separation of the catalyst from the reaction medium, reductive corrosion, improved regenerability, and enhanced product selectivity.Typically solid acids are zeolites, sulfated metal oxides, sulfonic group functional mesoporous silicas and acidic ion-exchange resins. However, their hydrophilic frameworks in nature result in the sorption of water in the processes of catalytic reactions, which will largely effect their catalytic activities and recyclability due to the water ususlly acts as a by-product,resulting in the opposite reactions and partial deactivation of the acidic sites.In this application,we try to design and synthesis of novel mesoporous polymer based solid acids through two novel routes:(i) sulfonation of superhydrophobic and super wettalibity mesoporous polydivinylbenzene (PDVB-SO3H)；(ii) copolymerization of DVB with sodium p-styrene sulfonate under solvothermal conditions.The resulted novel solid acids exhibit novel hydrophobicity and good wettability as compared with those of conventional solid acids.Characterizations show that PDVB-SO3H showed very high BET surface areas,novel hydrophobicity and good wettability for various organic substrates, which result in their much higher catalytic activities in esterification and hydration. Based on the above novel characters we will research their widely applications in biomass transformation for production of renewable and clean bio-energy.

酸催化是工业上最重要的催化类型之一，广泛的应用于石油化工和精细化工领域。目前，酸催化最需要解决的问题便是用固体酸来代替液体酸，固体酸具有易分离、腐蚀性小、再生方便等优点。常见的固体酸如：酸性沸石、硫化金属氧化物、离子交换树脂和磺酸功能化的介孔材料，然而他们具有亲水的骨架结构使得其在催化过程中容易吸附水，而水经常作为一类副产物出现，影响反应平衡和容易造成活性中心钝化，大大降低其催化活性和再生性能。本申请中我们将尝试合成具有新颖的疏水亲油骨架的介孔聚合物基的固体酸，合成主要通过磺化具有超疏水，超亲油的介孔聚二乙烯基苯或通过溶剂热的条件下二乙烯基苯与苯乙烯磺酸进行共聚等实现其合成。表征发现，该固体酸具有大的比表面积、优异的疏水性和对多种有机底物优异的浸润性，上述特点使得该材料在酯化、水合等反应中表现出不同寻常的催化活性，在此基础之上我们将研究该固体酸在催化生物质转化制备清洁可再生的生物能源。

催化生物质转化制备清洁生物能源对于克服化石能源短缺及环境压力具有重要的理论意义和实际应用价值。生物质转化制备生物能源主要通过催化动、植物油酯交换制备生物柴油和结晶纤维素解聚制备重要的化学中间体。而实现生物质转化最为有效的途径之一是酸催化过程，利用高效固体酸替代传统液体酸催化生物质转化是实现生物能源绿色、可持续制备的关键。本课题主要开发新型、骨架浸润性可控的多孔聚合型固体酸材料，实现生物质的高效催化转化制备生物柴油及化学中间体。固体酸通过溶剂热条件下二乙烯基苯与乙烯基吡啶、咪唑等共聚得到功能化纳米多孔聚合物，利用1,3-丙烷磺内酯进行季胺化和三氟甲烷磺酸进行酸交换，即可制备骨架浸润性可控的纳米多孔固体强酸；同时我们也可以在聚合的过程中引入苯乙烯磺酸钠盐，一步实现强酸性离子液体及磺酸根在多孔聚合物骨架上的接枝。表征发现，我们制备的材料具有丰富的纳米孔结构，大的比表面积，可控的骨架浸润性及强酸中心。催化测试发现，该课题制备的系列固体酸材料在催化植物油制备生物柴油及结晶纤维素解聚制备葡萄糖、果糖、HMF等反应中显示了优异的催化性能，达到的液体硫酸、盐酸的水平，优于均相酸性离子液体催化材料(J. Am. Chem. Soc. 2012, 134, 16948-16950，Applied Catalysis B: Environmental 2013, 136-137, 193-201)。如催化植物油制备生物柴油的过程中，常压条件，65度12小时内即可实现植物油到生物柴油的完全转化，同时我们利用该固体酸对催化结晶纤维素转化制备糖类等重要中间体的反应进行了初步探索，其催化性能远远优于常规固体酸（Chem. Comm. 2013, 49, 8456-8458）。同时，我们通过关联性研究工作，我们将固体酸材料的骨架拓展到多孔炭材料及介孔酚醛树脂骨架，包括多级孔炭及多孔类石墨烯材料，考察不同骨架结构及微纳米孔结构对于其催化性能的影响，其在催化生物质转化制备生物能源中仍然保持了优异的催化性能(Green Chemistry 2015, 17, 480，Catalysis Science&Technology 10.1039/c5cy01226k)。本课题对于开发新型高效的纳米多固体酸材料提供了新方法，利用其替代液体酸，实现生物能源的高效催化转化具有一定的研究意义。