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Kinetics, Mechanism, and Active Site Requirements for Hydrodeoxygenation over Reducible Metal Oxides

可还原金属氧化物加氢脱氧的动力学、机理和活性位点要求

基本信息

批准号：
1916133
负责人：
Praveen Bollini
金额：
$ 36.49万
依托单位：
University of Houston
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2019
资助国家：
美国
起止时间：
2019-09-01 至 2024-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1916133&HistoricalAwards=false
关键词：
Kinetics Mechanism Active Site Requirements

项目摘要

Bio-oils are obtained from the fast pyrolysis of biomass, and their conversion into fuels and chemicals represents a sustainable alternative to coal, natural gas, and petroleum sources. The critical step in upgrading bio-oil is the selective removal of oxygen atoms from the lignin-derived fraction under ambient pressures of hydrogen and in the presence of a catalyst (otherwise known as "hydrodeoxygenation"). The ideal catalyst for hydrodeoxygenation would be abundant, inexpensive and easy to handle, while also being active, selective, hydrogen efficient, stable, and regenerable. The goal of this research project is to develop a molecular-level understanding of the chemical and physical processes occurring during the hydrodeoxygenation of biomass-derived model compounds over a class of catalysts called reducible metal oxides. Primarily, the studies will focus on cerium oxide (ceria), a material widely used commercially as an oxygen storage component in automotive exhaust systems. The research project serves as a training ground for graduate and undergraduate students to perform cutting edge research. The researchers also will participate in outreach activities in the Houston area, including Energy Day and Chevron Girls Engineering the Future Day, and they will host high school students in the laboratory and provide them with hands-on research experience as part of Project ACS SEED.The fact that bulk ceria selectively cleaves carbon-oxygen bonds in biomass-derived model compounds raises interesting fundamental questions regarding the nature and density of oxygen vacancies in reducible metal oxides. The precise mechanism through which carbon-oxygen bond cleavage over ceria occurs will be studied via four experimental steps: (1) demonstration of the potential of bulk ceria as a hydrodeoxygenation catalyst; (2) elucidation of the mechanism of anisole hydrodeoxygenation over bulk ceria; (3) establishing the active site requirements for hydrodeoxygenation over cerium oxide; and (4) understanding the effect of doping on active site identity, density, and efficacy. This research project aims to optimize energy, cost, and atom-efficiency of biomass conversion processes by guiding the design of hydrodeoxygenation catalysts and clarifying the identity of the mechanistic steps involved in Mars-van Krevelen/reverse Mars-van Krevelen redox cycles, ubiquitous in the realm of bulk oxide catalysis.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.

生物油是从生物质的快速热解中获得的，它们转化为燃料和化学品是煤炭、天然气和石油来源的一种可持续的替代品。改进生物油的关键步骤是在常压氢气和催化剂存在的情况下选择性地脱除木质素衍生馏分中的氧原子(也称为加氢脱氧)。理想的加氢脱氧催化剂应该是丰富的、廉价的、易于操作的，同时还具有活性、选择性、氢效率、稳定性和可再生性。本研究项目的目标是在分子水平上了解生物质衍生的模型化合物在一类名为可还原金属氧化物的催化剂上加氢脱氧过程中发生的化学和物理过程。这些研究将主要集中在氧化铈(CeO2)上，这是一种被广泛用作汽车排气系统储氧元件的材料。该研究项目是研究生和本科生进行尖端研究的训练场。研究人员还将参加休斯顿地区的外联活动，包括能源日和雪佛龙女孩设计未来日，他们将在实验室接待高中生，并作为ACS SEED项目的一部分为他们提供实践研究经验。块状CeO2选择性地裂解生物质衍生模型化合物中的碳-氧键的事实提出了关于可还原金属氧化物中氧空位的性质和密度的有趣的基本问题。我们将通过四个实验步骤来研究CeO上发生碳氧键断裂的精确机制：(1)展示块状CeO作为加氢脱氧催化剂的潜力；(2)阐明块状CeO上苯甲醚加氢脱氧的机理；(3)确定CeO上加氢脱氧的活性中心要求；以及(4)了解掺杂对活性中心一致性、密度和有效性的影响。这项研究项目旨在通过指导加氢脱氧催化剂的设计，并澄清在MARS-VAN KREVIEN/MARS-VAN KREVREVEN反向氧化还原循环中涉及的机械步骤的一致性，来优化生物质转化过程的能源、成本和原子效率。该奖项反映了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。