Lewis acidic porous element organic frameworks for the selective catalytic transformation of monosaccharides

用于单糖选择性催化转化的路易斯酸性多孔元素有机骨架

• 批准号: 450360023
• 负责人: Dr. Irina Delidovich, Ph.D.
• 金额: --
• 依托单位: Institut für Verfahrenstechnik, Umwelttechnik und Technische Biowissenschaften (E166)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/450360023?language=en
• 关键词: Lewis; acidic; porous; element; organic

Element-organic frameworks are a rather young class of nanoporous inorganic-organic hybrid materials and offer high potential in heterogeneous catalysis. Especially tin-based materials are important based on the well-known catalytic properties of Sn-doped zeolites. Based on their active Lewis-acidic sites especially the conversion of biomass-based platform chemicals has been investigated in recent years and particularly with the isomerization of saccharides, a relatively new area for heterogeneous chemocatalysis has been opened up. The Sn-organic frameworks (Sn-OF) exhibit active Sn sites embedded in an organic matrix with the internal surface chemistry differing significantly from that of the zeolites. In preliminary work it was shown that the Sn-OF show a high activity for the conversion of sugars. However, the epimerization of the aldoses is preferably catalyzed instead of the isomerization of aldoses to ketoses in case of the zeolites. This invers selectivity can be explained by a different reaction mechanism, which is probably defined by the type of active sites and their chemical environment. This selective epimerization enables access to a large number of rare aldoses for use in the pharmaceutical and food industries. In this project, this catalytic system will be further investigated and developed in a complementary collaboration by two groups in technical chemistry from TU Darmstadt and RWTH Aachen University. At TUDA the Sn-OF synthesis will be systematically modified in order to tailor the type and number of active sites in the form of defects. An alternative synthesis route towards new materials with more precisely defined active sites will be developed and comprehensively characterized. The epimerization catalysis is carried out in a continuously operated fixed-bed reactor in order to determine the most important reaction parameters and to evaluate the technical feasibility. At higher temperatures, the formation of shorter-chain by-products for other bio-based value chains will be investigated. At RWTH the focus is on mechanistic studies of the epimerization and the characterization of the active sites in order to systematically derive structure-activity relationships for a further development of the catalysts. Finally, the preparation of rare aldoses is optimized through epimerization using the approach of preparative catalysis. Overall, the project deals with an innovative approach based on a new catalyst system for the selective transformation of monosaccharides. It combines basic research for new catalyst materials with the knowledge-based development of a new heterogeneous catalytic process for the utilization of renewable raw materials in new value chains.

元素-有机框架是一类相当年轻的纳米多孔无机-有机杂化材料，在多相催化方面具有很高的潜力。基于锡掺杂沸石众所周知的催化性能，锡基材料尤其重要。近年来，基于其活性路易斯酸性位点，特别是基于生物质的平台化学品的转化，特别是糖的异构化，已经开辟了多相化学催化的一个相对新的领域。 Sn-有机骨架（Sn-OF）表现出嵌入有机基质中的活性锡位点，其内表面化学性质与沸石的内表面化学性质显着不同。初步工作表明，Sn-OF 对糖的转化表现出很高的活性。然而，在沸石的情况下，优选催化醛糖的差向异构化而不是醛糖异构化为酮糖。这种逆选择性可以通过不同的反应机制来解释，该机制可能由活性位点的类型及其化学环境来定义。这种选择性差向异构化能够获得大量稀有醛糖，用于制药和食品工业。在该项目中，达姆施塔特工业大学和亚琛工业大学的两个技术化学小组将通过互补合作进一步研究和开发该催化系统。在 TUDA，Sn-OF 合成将被系统地修改，以定制缺陷形式的活性位点的类型和数量。将开发并全面表征具有更精确定义的活性位点的新材料的替代合成路线。差向异构催化在连续运行的固定床反应器中进行，以确定最重要的反应参数并评估技术可行性。在较高温度下，将研究其他生物基价值链的短链副产品的形成。 RWTH 的重点是差向异构化的机理研究和活性位点的表征，以便系统地导出结构-活性关系，以进一步开发催化剂。最后，利用制备催化方法通过差向异构化优化了稀有醛糖的制备。总的来说，该项目涉及一种基于新催化剂系统的创新方法，用于单糖的选择性转化。它将新型催化剂材料的基础研究与新型多相催化工艺的知识开发相结合，以在新价值链中利用可再生原材料。