CAREER: Engineering the Reactivity of Single Atom Electrocatalysts Beyond their Active Site

职业：设计单原子电催化剂的活性位点之外的反应性

• 批准号: 2340693
• 负责人: Joaquin Resasco
• 金额: $ 65万
• 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: 2024
• 资助国家: 美国
• 起止时间: 2024-06-01 至 2029-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2340693&HistoricalAwards=false
• 关键词: CAREER; Engineering; Reactivity; Single; Atom

Electricity generation from renewable sources, such as wind and sunlight, is becoming increasingly cheap and available. To meet our nation’s decarbonization goals, however, technologies are needed that can leverage this renewable electricity to produce useful chemicals and fuels with low carbon dioxide (CO2) emissions. Electrochemical processes are poised to address this critical need. For example, the electrochemical splitting of water can produce green hydrogen, while the oxidation of green hydrogen can yield carbon free energy on demand. But the viability of these processes depends on the performance and cost of catalytic materials needed for the electrochemical reactions. These catalysts are typically composed of rare and expensive metals such as platinum, palladium, and iridium. One strategy to improve the performance of these materials is to disperse the metal as individual atoms on a high surface area support. These “single-atom” catalysts (SACs) provide maximum metal usage efficiency and display unique catalytic properties. But key fundamental questions remain about how these catalysts carry out electrocatalytic reactions and what their true structure is under operating conditions. The project seeks to develop a fundamental understanding of electrochemical catalysis over SACs, and use this understanding to design new materials with improved performance and precious metal usage efficiency. The research will be integrated with educational efforts aimed at engaging students from underrepresented groups, particularly LatinX students, and exciting them about the role of catalysis in sustainability. Currently, single-atom electrocatalysts suffer from a lack of uniformity in their active site structures. To address that issue, the project will utilize atomic layer deposition (ALD) to synthesize catalysts with highly uniform catalytic active sites deposited on precisely synthesized metal oxide nanocrystalline supports. A combination of site-specific and in situ spectroscopies will be used to understand the atomic structure of the active sites and how their structure may evolve under reaction conditions. Having identified the nature of these active sites, links will be made between their structure and catalytic behavior. These structure-property relationships will be leveraged to design catalysts with optimal activity, systematically tuning the bonding of the metal site to the oxide support. This continuous tuning will be enabled by electrochemical ion insertion into the metal oxide support. In addition to understanding how the catalytic sites respond to changes in bonding to their support, the project will further demonstrate how their properties can be controlled by changing the electrochemical medium in which they operate. The insights developed in these studies will be used to design catalysts for selective electrochemical oxidation reactions using glycerol, a major byproduct of biodiesel, as a representative substrate.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.

可再生能源（例如风和阳光）的发电量变得越来越便宜且可用。但是，为了满足我们国家的脱碳目标，需要技术来利用这种可再生电力来生产有用的化学物质和二氧化碳（CO2）排放的有用的化学物质和燃料。电化学过程被中毒以满足这一关键需求。例如，水的电化学分裂可以产生绿色氢，而绿色氢的氧化可以按需产生碳自由能。但是这些过程的可行性取决于电化学反应所需的催化材料的性能和成本。这些催化剂通常由稀有且昂贵的金属组成，例如铂，钯和虹膜。提高这些材料性能的一种策略是将金属作为单个原子分散在高表面积的支持下。这些“单原子”催化剂（SAC）提供了最大的金属使用效率并显示出独特的催化特性。但是，关于这些催化剂如何进行电催化反应以及它们在操作条件下的真实结构是什么，仍然存在关键的基本问题。该项目旨在对SACS进行电化学催化的基本了解，并利用这种理解来设计具有提高性能和贵金属使用效率的新材料。这项研究将与旨在吸引来自代表性不足的群体（尤其是拉丁裔学生）的学生进行的教育工作，并激发他们对催化在可持续性中的作用。当前，单原子电催化剂的活性位点结构缺乏均匀性。为了解决该问题，该项目将利用原子层沉积物（ALD）来合成具有高度均匀的催化活性位点，这些催化剂沉积在精确合成的金属氧化金属氧化物纳米晶体支架上。位点特异性和原位光谱的结合将用于了解活性位点的原子结构，以及它们在反应条件下如何演变的结构。确定了这些主动位点的性质后，将在其结构和催化行为之间建立联系。这些结构 - 陶艺关系将被利用用于设计具有最佳活性的催化剂，并系统地调整金属位点与氧化物支撑的键合。通过电化学离子插入金属氧化物支撑，将启用这种连续的调整。除了了解催化位点如何响应与其支持的粘结变化响应外，该项目还将进一步证明如何通过更改其操作的电化学介质来控制其性质。这些研究中开发的见解将用于设计用于选择性电化学氧化反应的催化剂，该反应是Biodiesel的主要副产品，作为代表性的基质。该奖项反映了NSF的法定任务，并通过基金会的知识优点和广泛的影响来评估NSF的法定任务。