RUI: Quantifying Electron Donation in Metal-Support Interactions utilizing CO Adsorption Studies and Hammet Relationships for Catalyzed Organic Transformations

RUI：利用 CO 吸附研究和催化有机转化的 Hammet 关系量化金属-载体相互作用中的电子供给

• 批准号: 1160217
• 负责人: Bert Chandler
• 金额: $ 35万
• 依托单位: Trinity University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1160217&HistoricalAwards=false
• 关键词: RUI; Quantifying; Electron; Donation; Metal

Supported Au catalysts are now well established as extremely active catalysts for low temperature CO oxidation and a number of other reactions. Further advances in Au catalysis will require more detailed understanding of the important factors that govern its high catalytic activity and developing methods for tuning reaction selectivity. Many of these catalysts are comprised of Au nanoparticles dispersed on high surface area oxide carriers. The nanoparticles typically consist of tens to a few hundred atoms to maximize the number of surface atoms that are accessible to the reacting molecules. Because these particles are so small, they can be influenced by the underlying support. Further, although the support may influence the electronic properties of the nanoparticle, it is not clear how these changes affect the electronic structure of the transition state(s) for the key step(s) in the catalytic cycle. This project primarily involves developing new methods and approaches for characterizing how the underlying support changes the electronic properties of gold nanoparticles and determining how these electronic changes affect catalytic behavior. Professors Bert Chandler and Christopher Pursell at Trinity University, San Antonio, TX are teaming with Professor Robert Rioux at Pennsylvania State University to apply a known tool to aid in developing more understanding of this problem. Hammett studies have long been employed to help understand reaction mechanisms, and to evaluate charge build-up in the rate determining step. The Hammett methodology has been applied to several Au catalyzed reactions, and studies of benzyl alcohol oxidation by Au on different supports have shown significant differences, suggesting that the degree of charge building up on the organic fragment may be substantially influenced by the underlying support. These studies will be correlated with CO adsorption studies and X-ray absorption spectroscopy studies to characterize changes in the surface electronics as particle size and supports change. The aim is to provide a complete picture of how Au catalysts are affected by particle size and support effects.This RUI proposal will have a substantial impact on undergraduate education at Trinity University. Funds will be used to support several undergraduate researchers, who will be integral participants in this study. Further, initial research opportunities will be targeted to undergraduates early in their academic careers (1st and 2nd year students). This offers increased opportunities to capture students from underrepresented groups and capitalize on their interests in science, and thereby developing important human resources for our increasingly technical economy. Integrating the Trinity model that focuses on undergraduate research with a classic graduate experience at Penn State will provide a unique educational opportunity for all of the participants and will help to maximize the impact of the research performed by the undergraduates.

负载型Au催化剂目前已被公认为低温CO氧化和许多其它反应的极高活性催化剂。Au催化的进一步发展需要更详细地了解决定其高催化活性的重要因素，并开发调整反应选择性的方法。 这些催化剂中的许多由分散在高表面积氧化物载体上的Au纳米颗粒组成。 纳米颗粒通常由数十至数百个原子组成，以使反应分子可接近的表面原子的数量最大化。 由于这些颗粒非常小，它们可能会受到底层支撑的影响。 此外，尽管载体可能影响纳米颗粒的电子性质，但尚不清楚这些变化如何影响催化循环中关键步骤的过渡态的电子结构。该项目主要涉及开发新的方法和途径，用于表征底层支持物如何改变金纳米颗粒的电子性质，并确定这些电子变化如何影响催化行为。德克萨斯州圣安东尼奥的Trinity大学的Bert钱德勒教授和Christopher Pursell教授正在与宾夕法尼亚州立大学的Robert Rioux教授合作，应用一种已知的工具来帮助对这个问题有更多的了解。哈米特研究长期以来一直被用来帮助理解反应机理，并评估在速率决定步骤中的电荷积累。Hammett方法已被应用到几个Au催化的反应，和苯甲醇氧化的研究Au在不同的支持物上显示出显着的差异，这表明，在有机片段上的电荷积累的程度可能会受到基本的支持。这些研究将与CO吸附研究和X-射线吸收光谱研究相关联，以表征随着颗粒尺寸和支撑物的变化而发生的表面电子学变化。其目的是提供一个完整的图片Au催化剂是如何受到颗粒大小和支持效果。这个RUI的建议将对Trinity大学的本科教育产生实质性的影响。 资金将用于支持几名本科生研究人员，他们将成为本研究的整体参与者。 此外，最初的研究机会将针对本科生在他们的学术生涯早期（第一和第二年的学生）。 这提供了更多的机会来吸引来自代表性不足群体的学生，并利用他们对科学的兴趣，从而为我们日益技术化的经济开发重要的人力资源。 整合Trinity模式，重点是本科生研究与经典的研究生经验在宾夕法尼亚州立大学将提供一个独特的教育机会，为所有的参与者，并将有助于最大限度地提高由本科生进行的研究的影响。