Understanding the restructuring of model metal catalysts in reactant gases

了解反应气体中模型金属催化剂的重组

• 批准号: 1800601
• 负责人: Philippe Sautet
• 金额: $ 32.02万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-15 至 2022-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1800601&HistoricalAwards=false
• 关键词: Understanding; restructuring; model; metal; catalysts; Understanding; restructuring; model; metal; catalysts

Transition metals play key roles as catalysts in applications ranging from chemical and energy production to environmental remediation. Ample evidence indicates that catalyst structures do not remain unchanged during use. Instead, substantial and important restructuring occurs due to rearrangement of the metal atoms to make new structures. This restructuring has major consequences on catalytic properties, sometimes beneficial and sometimes not. Currently, scientists do not understand how the restructuring occurs at the atomic scale or under conditions similar to those used during catalysis. With funding from the NSF Chemical Catalysis Program, this research is providing a fundamental understanding of this chemistry under relevant gas pressures and reaction temperatures. It is being performed with a combination of cutting edge experiments by Dr. Franklin Tao from University of Kansas and computational modeling by Dr. Philippe Sautet from University of California Los Angeles. Drs. Tao and Sautet are incorporating this theoretical modeling and experimental work into the education and training of high school, undergraduate, and graduate students. Summer research internships for public high school students in their laboratories are also being provided. With funding from the Chemical Catalysis Program of the Division of Chemistry, Dr. Tao of the University of Kansas and Dr. Sautet from UCLA are combining advanced in situ/operando characterization and first principle based modelling to develop a fundamental understanding of the metal catalyst restructuring process. The research compares several metals (Pt, Pd, Ni, Co, Cu) under a pressure of carbon monoxide and other reactants. The experimental methods include high pressure scanning tunneling microscopy (HP-STM) and operando Ambient Pressure X-ray Photoelectron Spectroscopy. These surface-sensitive surface techniques allow for uncovering surface chemistry and structure of metals under a pressure of gas and provide an initial global view of the mechanism and determine global kinetic rates. Theoretical modelling brings an understanding of the atomistic elementary steps and of their energies. It also provides kinetic results that are compared with experimental measurement, hence validating the approach. Since large systems are required for the calculation, energies are obtained by using an accurate high dimensional neural network potential, previously trained from a density functional theory database. The influence of restructuring on catalytic reaction is being explored with the example of the water-gas shift reaction on Pt and Cu surfaces. Drs. Tao and Sautet are developing an outreach program focused on introducing high-school students to model catalysis research and on undergraduate student training.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.

过渡金属在从化学和能源生产到环境修复的应用中起关键作用。充分的证据表明，催化剂结构在使用过程中不会保持不变。取而代之的是，由于金属原子的重新排列以制造新的结构，进行了实质而重要的重组。这种重组对催化特性产生了重大影响，有时是有益的，有时是有益的。当前，科学家不了解重组是如何在原子量表或类似于催化过程中使用的条件发生的。随着NSF化学催化计划的资金，这项研究在相关气压和反应温度下提供了对该化学的基本理解。它是由堪萨斯大学富兰克林·陶（Franklin Tao）博士和加利福尼亚大学洛杉矶分校的菲利普·萨特特（Philippe Sautet）博士组合进行的尖端实验的结合。博士。陶和索特将这种理论建模和实验性工作纳入了高中，本科和研究生的教育和培训。还提供了实验室中公立高中生的夏季研究实习。借助化学级化学催化计划的资金，堪萨斯大学的陶博士和加州大学洛杉矶分校的Sautet博士正在结合先进的原位/操作表征和第一个基于原理的建模，以发展对金属催化剂重组过程的基本了解。该研究比较了一氧化碳和其他反应物的压力下的几种金属（PT，PD，NI，CO，CU）。实验方法包括高压扫描隧道显微镜（HP-STM）和Operando环境压力X射线光电子光谱。这些表面敏感的表面技术允许在气体压力下发现金属的表面化学和结构，并提供了机制的最初全局视图并确定全局动力学速率。理论建模带来了对原子基本步骤及其能量的理解。它还提供了将动力学结果与实验测量进行比较，因此可以验证该方法。由于计算需要大型系统，因此使用准确的高维神经网络电位获得了能量，该电位先前从密度功能理论数据库中训练。在Pt和Cu表面上，正在探索重组对催化反应的影响。博士。道和索特（Tao and Sautet）正在制定一项旨在介绍高中生的外展计划，以模拟催化研究和本科生培训。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子的评估来支持支持的，并具有更广泛的影响。