CAS: Fundamental Experimental-Theoretical Investigations of New Metal Alloy Nanocatalysts for Natural Gas Repurposing

CAS：用于天然气再利用的新型金属合金纳米催化剂的基础实验理论研究

• 批准号: 2109120
• 负责人: Simon Humphrey
• 金额: $ 58.93万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-01-01 至 2024-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2109120&HistoricalAwards=false
• 关键词: CAS; Fundamental; Experimental; Theoretical; Investigations

With the support of the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry, Profs. Simon M. Humphrey and Graeme Henkelman at the University of Texas at Austin are leading a highly collaborative research program involving the synthesis and reactivity studies of nano-sized alloys capable of converting methane into stable liquid fuels such as methanol, at the location where the methane is released. Meanwhile, natural gas flaring is an increasingly significant environmental issue worldwide and particularly in the USA. Natural gas (i.e., methane) that is released at oil recovery sites or in refineries is remediated by direct combustion to give carbon dioxide. While methane is a much more powerful greenhouse gas than carbon dioxide, the act of flaring still wastes the methane and adds millions of tones of extra carbon dioxide into the atmosphere each year. This is because compression of methane for transportation and eventual use is not cost-effective. This research project is fundamental and aims to understand how certain compositions of alloys of non-precious metals can perform the target reactions in a controlled and desirable manner. The scientific project is also significantly enhanced through integration with an innovative undergraduate educational program, called the Austin-International Framework (AIF), which provides a fully immersive, scholarship-supported international exchange experience to UT Austin undergraduates. It provides students the unique opportunity to broaden their horizons, while simultaneously earning course credit for their research experiences.This a collaborative experimental-computational research program between the groups of Profs. Simon M. Humphrey and Graeme Henkelman at the University of Texas at Austin. The overarching aims are to leverage expertise in the formation of novel metallic nanoalloys via microwave-assisted heating techniques, and to use theory in silico to guide synthetic studies and to elucidate the resulting reactivity of the nanoparticle catalysts, as a function of surface structure and composition. The specific goals of this project are to prepare new binary and ternary catalysts using combinations of catalytically less valuable and abundant coinage metals along with more highly oxophilic metals such as Ru and Re, to generate systems that can mimic the reactivity of scarcer noble metals. In addition to model gas-phase chemical reaction studies that mimic realistic reaction conditions, structure-function relationships will be elucidated using a palette of spectroscopic techniques (e.g., electron microscopy, total X-ray scattering, extended X-ray fine structure, chemisorption, etc.), to provide realistic theoretical models at the atomic scale. This structural information will then be used to build and refine theoretical models that can identify then most important active site ensembles. Ultimately this enables accurate predictions of reactivity and selectivity, which can be leveraged to inform future synthetic targets, toward the identification of eventual catalysts with desired reactivity: those that are able to selectively activate CH4 to CH3 and H in the presence of atomic oxygen.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.

在化学系高分子、超分子和纳米化学项目的支持下，Profs.德克萨斯大学奥斯汀分校的 Simon M. Humphrey 和 Graeme Henkelman 正在领导一项高度合作的研究项目，涉及纳米级合金的合成和反应性研究，这些合金能够将甲烷转化为稳定的液体燃料，例如甲醇，在甲烷产生的地方被释放。 与此同时，天然气燃烧是全球范围内日益严重的环境问题，特别是在美国。 采油场或炼油厂释放的天然气（即甲烷）通过直接燃烧产生二氧化碳进行修复。 虽然甲烷是一种比二氧化碳威力更大的温室气体，但燃烧行为仍然浪费了甲烷，并每年向大气中增加了数百万吨的额外二氧化碳。 这是因为压缩甲烷用于运输和最终使用并不具有成本效益。 该研究项目具有基础性，旨在了解非贵金属合金的某些成分如何以受控和理想的方式进行目标反应。 该科学项目还通过与创新的本科教育计划（称为奥斯汀国际框架（AIF））的整合而得到显着增强，该计划为德州大学奥斯汀分校的本科生提供完全身临其境的、由奖学金支持的国际交流体验。 它为学生提供了独特的机会来拓宽他们的视野，同时为他们的研究经验赢得课程学分。这是教授小组之间的合作实验计算研究项目。德克萨斯大学奥斯汀分校的西蒙·汉弗莱 (Simon M. Humphrey) 和格雷姆·亨克尔曼 (Graeme Henkelman)。 总体目标是利用微波辅助加热技术形成新型金属纳米合金的专业知识，并利用计算机理论指导合成研究并阐明纳米颗粒催化剂的反应性，作为表面结构和成分的函数。 该项目的具体目标是使用催化价值较低且丰富的造币金属与亲氧性较高的金属（例如钌和铼）的组合来制备新的二元和三元催化剂，以生成可以模拟稀有贵金属反应性的系统。 除了模拟真实反应条件的气相化学反应模型研究之外，还将使用一系列光谱技术（例如电子显微镜、总 X 射线散射、扩展 X 射线精细结构、化学吸附、等），以提供原子尺度的现实理论模型。 然后，该结构信息将用于构建和完善理论模型，该模型可以识别最重要的活性位点集合。 最终，这能够准确预测反应性和选择性，从而为未来的合成目标提供信息，从而识别具有所需反应性的最终催化剂：那些能够在原子氧存在下选择性地将 CH4 活化为 CH3 和 H 的催化剂。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。