Collaborative Research: Highly Selective Photocatalysis on TiO2 with Atomically Dispersed Active Centers

合作研究：具有原子分散活性中心的二氧化钛的高选择性光催化

• 批准号: 1924689
• 负责人: Dunwei Wang
• 金额: $ 30.26万
• 依托单位: Boston College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2023-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1924689&HistoricalAwards=false
• 关键词: Collaborative; Research; Highly; Selective; Photocatalysis

Catalysts accelerate chemical reactions toward preferred products with significant savings in energy and capital costs. Photocatalysts - those that rely on the sun's energy - offer a path to sustainable manufacturing of fuels and chemicals, and also facilitate remediation of environmental pollutants. The project will investigate novel photocatalyst designs for upgrading natural gas to higher-value products and clean-up of nitric oxide from air pollutants. The research will be supplemented by a broad range of educational and outreach activities aimed primarily at K-12 and undergraduate students from underrepresented backgrounds.The project enlists the expertise of three investigators with skills in catalyst synthesis, spectroscopic characterization techniques, and computational catalysis to prepare and characterize structurally well-defined and atomically-dispersed active sites on heterogeneous catalysts. The catalysts will be evaluated for their ability to control the product selectivity of photo-driven reactions and to elucidate the corresponding reaction mechanisms. This project responds to a critical challenge in heterogeneous catalysis that traditional synthesis methods often lead to a variety of catalytic sites that are structurally poorly defined. This diversity of active sites leads to poor reaction selectivity and hinders elucidation of reaction mechanisms. The researchers will address these challenges by synthesizing atomically-dispersed active centers, mononuclear metal sites and surface oxygen vacancies, on titanium dioxide, a prototypical photocatalyst. The project focuses on two technologically important reactions, the oxidation of methane to methanol and the reduction of NO to dinitrogen. The effort involves characterization of the catalysts with advanced techniques, such as HAADF-STEM and EXAFS. Operando infrared, Raman, and X-ray spectroscopies will be employed to provide insights into the mechanism of the surface reactions. DFT calculations will further complement the mechanistic information. The project is expected to generate novel insights into the factors that govern the reaction selectivity of heterogeneous catalytic reactions. The team will pursue a multi-pronged approach to engage underrepresented minorities in this research at their respective institutions and to educate the general public about photocatalysis. Specific activities include participation in the NSF-sponsored Research Experience for Undergraduates (REU) Program, an innovative course for freshmen undergraduate students whose primary declarations are not in the sciences, engagement in outreach activities with local high schools, and a collaborative effort with high-school teachers to introduce students to molecular modeling.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.

催化剂加速化学反应，生成首选产品，并显着节省能源和资本成本。 光催化剂——依赖于太阳能的光催化剂——为燃料和化学品的可持续制造提供了一条途径，也有利于环境污染物的修复。 该项目将研究新型光催化剂设计，将天然气升级为更高价值的产品，并清除空气污染物中的一氧化氮。 该研究将得到广泛的教育和外展活动的补充，这些活动主要针对 K-12 和来自代表性不足背景的本科生。该项目聘请了三名研究人员的专业知识，他们拥有催化剂合成、光谱表征技术和计算催化方面的技能，以准备并表征多相催化剂上结构明确且原子分散的活性位点。 将评估催化剂控制光驱动反应的产物选择性并阐明相应反应机制的能力。 该项目应对了多相催化中的一个关键挑战，即传统的合成方法通常会导致各种结构上不明确的催化位点。活性位点的多样性导致反应选择性差并阻碍了反应机制的阐明。 研究人员将通过在典型光催化剂二氧化钛上合成原子分散的活性中心、单核金属位点和表面氧空位来应对这些挑战。 该项目重点关注两个技术上重要的反应，即甲烷氧化为甲醇和NO还原为氮气。 这项工作涉及利用 HAADF-STEM 和 EXAFS 等先进技术对催化剂进行表征。 Operando 红外、拉曼和 X 射线光谱将用于深入了解表面反应的机制。 DFT 计算将进一步补充机械信息。 该项目预计将对控制多相催化反应的反应选择性的因素产生新的见解。 该团队将采取多管齐下的方法，让代表性不足的少数群体参与各自机构的这项研究，并对公众进行光催化方面的教育。 具体活动包括参与 NSF 资助的本科生研究体验 (REU) 计划，该计划是为主要申报内容不是科学领域的新生本科生开设的创新课程，参与当地高中的外展活动，以及与高中的合作。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。