英文摘要: | 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. |