CAREER: Toward unprecedented selectivities in C-O bond cleavage reactions using Fe-based bimetallic catalysts

摘要标题：木质纤维素生物质转化所需的C-O键裂解反应的选择性双金属非贵金属磷化物催化剂。摘要：生物质燃料和化学品的利用是一个可持续和安全的国家能源计划的重要组成部分，但需要新的催化剂的设计和开发，以实现这一目标。具体来说，需要选择性切割C-O键的催化剂，这种催化剂在生物质中普遍存在，以有效地将生物质转化为增值的液体产品和燃料。由圣母大学的PI Jason Hicks开发的新型铁基双金属催化剂解决了这一需求，使用富含地球的过渡金属，不仅对这些反应具有高度选择性，而且比现有的催化剂和技术具有环境效益。利用这项NSF CAREER奖，Hicks教授将寻求最佳的键断裂反应催化剂，并将寻找一些基本因素，为这些催化剂的改进指明方向。除了具体的研究目标之外，这个CAREER项目还通过规划本科生和高中生在实验室的研究、开发新的多相催化剂设计课程和在圣母大学的研究生研究研讨会来促进学生的教育。这些活动将研究与未来科学家的教育结合起来，以应对可持续能源的挑战。该项目的主要目标是深入研究基于Fe和Mo的双金属磷化物催化剂在生物质模型化合物的C-O键裂解反应中的稳定性、反应性和选择性，针对那些与生物基原料最相关的键。与单金属催化剂相比，双金属催化剂在许多反应中往往表现出更高的催化活性和/或选择性，包括生物燃料和生物衍生化学品的生产。因此，通过加入另一种金属或添加剂来调整催化剂性能的能力可以对反应途径产生深远的影响，并提供对催化选择性的更多控制。CAREER计划主要关注这些重要反应的过渡金属磷化物催化剂。金属磷化物是一类根据所使用的金属、金属与磷的比例和合成参数具有可调结构和化学特性的材料。磷化物可以合成为定义明确的结晶粉末、纳米颗粒或负载催化剂，这取决于所需的应用。Hicks小组对这些催化材料的实验研究表明，酚类模型化合物的C-O键裂解可能的选择性大于90%。在这些初步结果的基础上，提出的项目涉及合成具有不同金属成分的独特双金属磷化物催化剂，以最终控制催化剂的性能。此外，还将研究使用这些催化剂对酚类化合物加氢脱氧的反应机理，以及生物油中发现的其他含氧化合物。结合体积和表面表征技术，将确定催化剂结构/性能关系，以阐明这些催化材料的性质。最终，该项目旨在通过合理的催化剂设计来提高木质素和木质纤维素材料向液体运输燃料和化学品的转化，从而开发可持续的能源过程和清洁燃料生产途径。

Abstract Title: Selective, bimetallic non-noble metal phosphide catalysts for C-O bond cleavage reactions necessary for lignocellulosic biomass conversion.Abstract Content:Utilization of biomass for fuels and chemicals is an important component of a sustainable and secure national energy plan, but the design and development of new catalysts is needed to enable this aim. Specifically, catalysts that selectively cleave C-O bonds, which are ubiquitous in biomass, are needed to efficiently and effectively convert biomass to value-added liquid products and fuels. The novel, iron-based bimetallic catalysts developed by PI Jason Hicks at the University of Notre Dame address this need using earth abundant transition metals which are not only highly selective for these reactions but also offer environmental benefits over existing catalysts and technologies. Using this NSF CAREER award, Prof. Hicks will seek the optimum catalysts for the bond breakage reactions, and will seek some fundamental factors that will point directions for improvements in these catalysts. In addition to the specific research aims, this CAREER project also benefits student education by planning for research in the laboratory by undergraduate and high school students, and development of a new Heterogeneous Catalyst Design course and Graduate Research Symposium at the University of Notre Dame. These activities integrate research with education of future scientists to address the challenge of sustainable energy.The primary goals of this project are to thoroughly investigate the stability, reactivity, and selectivity of bimetallic Fe and Mo based phosphide catalysts for C-O bond cleavage reactions of biomass model compounds, targeting those bonds most relevant to bio-based feedstocks. Bimetallic catalysts often exhibit enhanced catalytic activity and/or selectivity compared to monometallic catalysts for many reactions, including the production of biofuels and bio-derived chemicals. The ability to tune the performance of a catalyst by incorporating another metal or additive can, therefore, have profound effects on the reaction pathway and provide more control over the catalytic selectivity. The CAREER proposal is focused primarily on transition metal phosphide catalysts for these important reactions. Metallic phosphides are a class of materials that have tunable structural and chemical characteristics based on the metals used, ratio of metals to phosphorus, and synthesis parameters. Phosphides can be synthesized as well-defined crystalline powders, nanoparticles, or supported catalysts, depending on the desired application. Experimental studies by the Hicks group on these catalytic materials indicate possible selectivities for C-O bond cleavage of phenolic model compounds greater than 90%. Based on these initial results, the proposed Project involves the synthesis of unique bimetallic phosphide catalysts with various metal compositions to ultimately control the catalyst performance. Additionally, reaction mechanisms for the hydrodeoxygenation of phenolic compounds using these catalysts, as well as other oxygenated compounds found in bio-oils, will be studied. Together with bulk and surface characterization techniques, catalyst structure/performance relationships will be determined to elucidate the properties of these catalytic materials. Ultimately, the PI aims to develop sustainable energy processes and pathways to cleaner fuels production by leveraging rational catalyst design to enhance the conversion of lignin and lignocellulosic materials to liquid transportation fuels and chemicals.