EAGER: Catalytic Reaction Coupling of Bio-oil Hydrodeoxygenation and Alkane Dehydrogenation

开发经济上可行的从木质纤维生物质热解产生的生物油生产液体运输燃料的技术是一项具有重要社会和环境可持续性的重大挑战。其中一个障碍是，通过一种名为催化加氢脱氧(HDO)的化学反应从生物油中去除不需要的氧气需要很高的氢气。另一方面，最近页岩气技术的发展导致了大量未得到充分利用的低碳烷烃的生产，这可以作为生物油HDO的氢源。这一项目的主要目的是探索使用新型双功能催化剂家族的生物油HDO和轻(C2-C4)烷烃脱氢的直接偶联反应。探索性研究的中心假设是，由贵金属(如铂)和亲氧金属(如钼)组成的综合催化剂设计将使所提出的反应偶联方案成为可能。根据热力学分析，这样的催化剂概念在理论上是可能的，但尚未得到实验证明，也仍未得到测试。如果成功，这种催化剂将从根本上改变现有的生物油升级和烯烃生产方法。为了探索这一概念的可行性，将进行三个具体的研究目的：(1)确定金属中心大小和金属-金属中心距离的影响；(2)揭示生物油HDO中心的亲氧性的影响；(3)表征载体组成的影响。为了在分子水平上了解表面反应路径，将在纳米尺度上合成结构可控的双功能催化剂。催化剂活性将根据流动反应器实验中期望和不期望的产物的产率来测量。产物分布依赖于(1)贵金属中心的大小，(2)DH和HDO中心之间的距离，(3)亲氧金属中心的金属-氧键强度，以及(4)金属氧化物载体的组成。提出的探索性研究可能有助于从根本上理解表面反应的化学动力学中的催化几何和电子效应。除了培训两名研究生外，首席研究人员还计划将研究成果整合到本科和研究生课程中。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The development of economically viable techniques for manufacturing liquid transportation fuels from bio-oils produced by pyrolysis of lignocellulosic biomass is a grand challenge with important societal and environmental sustainability implications. One of the obstacles is the high hydrogen requirement for removing the undesired oxygen from the bio-oil via a chemical reaction called catalytic hydrodeoxygenation (HDO). On the other hand, recent developments in shale gas technologies have led to the production of vast amounts of under-utilized light alkanes, which could serve as a source hydrogen for bio-oil HDO. The main objective of this EAGER project is to explore the direct coupling reaction of bio-oil HDO and light (C2-C4) alkane dehydrogenation (DH) using a new family of bifunctional catalysts.The central hypothesis of the proposed exploratory research is that an integrated catalyst design, consisting of a precious metal (e.g., Pt) and an oxophilic metal (e.g., Mo) on a low acidic and weak electronegative metal oxide support (e.g., TiO2), will enable the proposed reaction coupling scheme. Such a catalyst concept is theoretically possible, based on thermodynamic analysis, but has not been experimentally proven and remains untested. If successful, such a catalyst will radically transform the existing bio-oil upgrading and olefin production methods. Three specific research aims will be pursued to explore the feasibility of this concept: (1) the effect of metal site size and metal-metal site distance will be determined; (2) the influence of oxophilicity of the bio-oil HDO sites will be revealed; (3) the impact of support composition will be characterized. To obtain molecular-level understanding of the surface reaction pathways, the bifunctional catalysts will be synthesized with their structures controlled at the nanoscale. Catalyst activity will be measured based on the yields of desired and undesired products from the flow reactor experiments. The dependence of product distribution on (1) the size of the precious metal site, (2) the distance between the DH and HDO sites, (3) metal-oxygen bond strength of the oxophilic metal site, and (4) the compositions of the metal oxide support will be determined. The proposed exploratory research may lead to fundamental understanding of the catalytic geometric and electronic effects on the chemical kinetics of the surface reactions. In addition to training two graduate students, the principal investigators plan to integrate research outcomes into undergraduate and graduate curricula.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.