Probing metal catalyst-support interactions using small cluster models: Gas-phase reactivity studies, anion photoelectron spectroscopy, and DFT calculations

化学催化计划支持印第安纳大学的Caroline C.Jarroeld教授研究明确定义的团簇模型的电子和结构性质之间的相互作用，这些模型用于研究催化剂-载体和催化剂-载体-底物相互作用的固有局部现象。一种三管齐下的方法被用来表征已被确定为对工业上重要的水-气变换反应特别活跃的新型催化剂的簇模型。(水煤气变换反应催化结合水和一氧化碳产生氢气和二氧化碳。)模型团簇的阴离子光电子能谱(PE)测量提供了团簇的质量比电子轮廓，它是金属组成和氧含量的函数。通过将实验PE谱与计算结果相一致来确定团簇结构，对团簇的气相反应性研究允许团簇反应性与团簇分子和电子结构之间的关联。第一系列的研究集中在最近的文献启发下的含铂的团簇系统。还探索了具有相似(和可能改进的)属性的可选的和更便宜的集群模型，并与已知的工业催化剂进行了比较。这些研究的更广泛影响包括产生可为设计改进的、更低成本和更节能的水煤气变换反应催化剂提供信息的知识，以及评估用于研究非传统氧化态金属氧化物的新计算方法。此外，新一代科学家接受了了解与工业相关的催化反应的培训。金属氧化物经常被用作工业催化剂。它们的组成经常被优化，以便催化剂在较低的温度下运行，或者使用更便宜和更容易获得的材料。这项研究项目旨在确定支配水煤气变换反应所用催化剂的基本分子尺度特征。水煤气变换反应将水和一氧化碳结合起来，生成氢气和二氧化碳。实验和计算工具被用来创造和研究在这一工业重要反应中使用的定义明确的纳米和亚纳米尺度的金属氧化物的性质。该项目在技术上的更广泛影响包括减少这一工业过程的能源消耗。该项目的一个更直接和更直接的结果是，利用以实际工业问题为动机的项目为中心，利用计算和实验平台，对青年男女进行科学方法培训。

The Chemical Catalysis Program supports the efforts of Professor Caroline C. Jarrold from Indiana University to study the interplay between electronic and structural properties of well-defined cluster models used to study the inherently local phenomenon of catalyst-support and catalyst-support-substrate interactions. A three-pronged approach is used to characterize cluster models of new catalysts that have been identified as particularly active toward the industrially-important water-gas shift reaction. (The water gas shift reaction catalytically combines water and carbon monoxide to produce dihydrogen and carbon dioxide.) Anion photoelectron (PE) spectroscopy measurements on model clusters provide a mass-specific electronic profile of the clusters as a function of both metal composition and oxygen content. Cluster structures are determined by reconciling experimental PE spectra with computational results and gas-phase reactivity studies on the clusters allow for the correlation between cluster reactivity and cluster molecular and electronic structures. The first series of studies focus on platinum-containing cluster systems inspired by recent literature. Alternative and less expensive cluster models rationalized to have similar (and possibly improved) attributes are also explored and compared to known industrial catalysts. The broader impacts of these studies include the generation of knowledge that can inform the design of improved, lower-cost and more energy-efficient catalysts for water gas shift reactions and the evaluation of new computational approaches used to study metal oxides in non-traditional oxidation states. In addition, a new generation of scientists are trained to understand industrially-relevant catalysis reactions.Metal oxides are often used as industrial catalysts. Their composition is often optimized so that the catalysts operate at lower temperatures or with cheaper and more readily available materials. This research project is designed to determine the essential molecular-scale features that govern catalysts used in the water gas shift reaction. The water gas shift reaction combines water and carbon monoxide to make dihydrogen and carbon dioxide. Experimental and computational tools are used to create and study the properties of well-defined nano- and sub-nanometer scale bits of metal oxides used in this industrially important reaction. The technical broader implications of this project include a reduced energy consumption for this industrial process. A more immediate and direct outcome of this project is the training of young women and men in the scientific method using computational and experimental platforms centered on a project that motivated by practical industrial concerns.