Characterizing Surface Binding and Activation of Substrates in Aqueous-Phase Heterogeneous Catalysis (TSE03-C)

该项目解决了快速发展的生物可再生能源催化转化领域的关键研究需求。发酵产生的有机酸是一类重要的可再生资源衍生化合物；它们由生物质大量制成，可以转化为各种药品、食品、聚合物、溶剂和其他产品的基本组成部分。研究了在水环境下，多相金属催化剂对有机酸的吸附和加氢过程。有机酸的反应和吸附研究以及酸与其他物质的组合将更好地了解有机酸及其反应产物在不同金属催化剂上的结合强度和反应活性，从而为最终定制特定有机酸底物加氢的催化剂性能提供基础。这项工作的其他方面将澄清一些关键问题，如水对催化剂金属的作用，CO等毒物的影响，以及产物中手性的保留和产生。此外，由于加氢和脱氢共享化学途径，这项工作对作为清洁能源的生物质制氢具有启示意义。从环境的角度来看，与使用均相催化剂或传统的氢化物试剂化学相比，金属催化剂在水中的多相加氢使催化剂易于分离和再利用，避免了有机溶剂，大大减少了废物的产生。因此，这种“绿色”氢化途径代表了未来“生物质精炼厂”所需的主要支持技术。最后，这项努力支持了教育下一代科学家的更大使命，他们将负责用可再生、可持续的资源生产我国的化学品和燃料。

This project addresses critical research needs in the rapidly developing area of catalytic conversion of biorenewables. Organic acids produced via fermentation constitute an important class of renewable resource-derived compounds; they are made in large quantities from biomass and can be converted into a variety of building blocks for pharmaceuticals, foods, polymers, solvents, and other products. The research will characterize organic acid adsorption and hydrogenation on heterogeneous metal catalysts in an aqueous environment. The reaction and adsorption studies to be conducted with organic acids and combinations of acids with other species will develop a better understanding of binding strengths and reactivities of organic acids and their reaction products on different metal catalysts, thus providing a foundation for ultimately tailoring catalyst properties for hydrogenation of specific organic acid substrates. Additional aspects of the work will clarify key issues such as the role of water on the catalyst metal, the effect of poisons such as CO, and retention and generation of chirality in the product species. Further, because hydrogenation and dehydrogenation share chemical pathways, this work has implications for hydrogen generation from biomass as a clean energy source. From an environmental standpoint, heterogeneous hydrogenation over metal catalysts in water allows easy catalyst separation and reuse, avoids organic solvents, and greatly reduces waste generation in comparison to use of homogeneous catalysts or traditional hydride reagent chemistry. This "green" hydrogenation pathway thus represents a primary class of enabling technologies needed for the "biomass refinery" of the future. Finally, this effort supports the larger mission of educating the next generation of scientists, who will be responsible for producing our nation's chemicals and fuels from renewable, sustainable resources.