CAS: Improving the Efficiency of Supported Palladium Catalysts for Methane Complete Combustion Using Monodisperse Nanocrystals

开发甲烷完全氧化的催化剂对于避免这种强大的温室气体的排放，同时利用它作为能源是很重要的。最近的研究表明，从大气中清除甲烷可以将温室气体潜力减少到工业化前的水平，从而使大气层恢复。目前，钯是进行该反应的最佳金属，但如何提高其活性以更好地利用这种昂贵的金属还不清楚。在这个项目中，斯坦福大学的Cargnello博士正在研究钯如何激活甲烷中的C-H键，并将其完全氧化为二氧化碳和水。使用由胶体纳米晶体制备的精确控制的催化材料，Cargnello博士正在揭示有关钯催化行为及其最佳利用的新细节。Cargnello博士积极致力于通过与来自不同背景的本科生、高中生和教师的研究经验来增加斯坦福大学工程学院的多样性。这些活动包括前往高中，向年轻学生介绍STEM和化学工程的机会，目的是鼓励不同的学生考虑这些领域的职业。在化学系化学催化计划的资助下，斯坦福大学的Cargnello博士正在开发对催化甲烷全燃烧中负载钯化学的基本理解。有效使用钯催化剂将有助于减少这种强大的温室气体的排放。许多问题有关的复杂的钯氧化态化学作为反应条件的函数，其相关性与载体材料，促进剂的存在下，催化剂在高温下的稳定性，并在水的存在下仍然存在争议。所有这些方面都是充分理解催化剂行为的关键，并找到进一步提高Pd效率和利用率的方法。使用精确的纳米晶体作为均匀催化剂的构建块是该项目的重点，以确定Pd活性相，氧化态和相关反应条件下的结构;了解Pd失活;以及促进相如何改变Pd的结构和氧化态。催化研究得到了与SLAC国家实验室的科学家合作使用原位和操作光谱学以及DFT计算的协作努力的支持。Cargnello博士积极致力于增加工程学院的多样性，并向年轻一代介绍STEM和化学工程的机会，鼓励不同的学生考虑在科学和工程领域的职业生涯。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。

Developing catalysts for the complete oxidation of methane is important to avoid emissions of this powerful greenhouse gas while taking advantage of it as an energy resource. Recent studies show that removing methane from the atmosphere could reduce greenhouse gas potential to pre-industrial levels, thus resulting in atmospheric restoration. Currently, palladium is the best metal to perform this reaction, but it is not well understood how to improve its activity to make better use of this expensive metal. In this project, Dr. Cargnello of Stanford University is developing an understanding of how palladium activates the C-H bonds in methane and oxidizes it completely to carbon dioxide and water. Using precisely controlled catalytic materials prepared from colloidal nanocrystals, Dr. Cargnello is uncovering novel details about the catalytic behavior of palladium and its optimal utilization. Dr. Cargnello is actively engaged in efforts to increase diversity in the Stanford School of Engineering through research experiences with undergraduates, high-school students, and teachers from diverse backgrounds. These activities, which include trips to high schools to inform younger students about STEM and chemical engineering opportunities, have the goal to encourage diverse students to consider careers in these fields.With funding from the Chemical Catalysis Program of the Division of Chemistry, Dr. Cargnello of Stanford University is developing a fundamental understanding of the chemistry of supported palladium in the catalytic total methane combustion. Efficient use of palladium catalysts will help to decrease emissions of this powerful greenhouse gas. Many questions related to the complex palladium oxidation state chemistry as a function of reaction conditions, its correlation with support materials, the presence of promoters, and catalyst stability at high temperature and in the presence of water remain debated. All these aspects are key to fully understand catalyst behavior, and to find ways to further increase Pd efficiency and utilization. The use of precise nanocrystals as building blocks of uniform catalysts is a key focus in this project in order to identify Pd active phase, oxidation state, and structure under relevant reaction conditions; understand Pd deactivation; and how promoting phases change the structure and oxidation state of Pd. The catalytic studies are supported by collaborative efforts using in-situ and operando spectroscopy and DFT calculations in collaboration with staff scientists at SLAC National Laboratory. Dr. Cargnello is actively engaged in efforts to increase diversity in the School of Engineering and inform younger generations about STEM and chemical engineering opportunities, to encourage diverse students to consider a career in the science and engineering fields.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.