Kinetics and Energetics of Gas Phase Metal Cluster Catalysis

在化学部实验物理化学计划的支持下，欧文将研究气相转变金属团簇与吸附物之间的相互作用。用能量分辨碰撞诱导解离和时间分辨光解离实验测量了吸附在团簇上的结合能。将统计速率理论应用于团簇解离数据，得到了解吸能。主要的进展包括开发光解离动力学技术以获得裸金属团簇和吸附在团簇上的结合能；探索作为实际催化剂的气相过渡金属团簇；以及检验与催化相关的小团簇/配体体系。我们将使用导引离子束串联质谱仪来收集数据。本项目中测量的数据对于确定催化反应机理和绘制反应路径非常重要。这里研究的团簇是催化系统的模型，因为它们模拟了构成工业过程中使用的催化剂的反应中心的小金属微晶。气相团簇本身也可以作为催化剂，例如在铂团簇阴离子将一氧化碳氧化为二氧化碳的过程中。

In this project supported by the Experimental Physical Chemistry Program of the Chemistry Division, Ervin will investigate the interactions between gas-phase transition metal clusters and adsorbates. Energy-resolved collision-induced dissociation and time-resolved photodissociation experiments are used to measure the binding energies of adsorbates on the clusters. Statistical rate theory is applied to the cluster dissociation data to obtain desorption energies. Major thrusts include exploitation of photodissociation dynamics techniques to obtain binding energies of bare metal clusters and of adsorbates on clusters; exploration of gas-phase transition metal clusters as actual catalysts; and examination of small cluster/ligand systems of relevance to catalysis. A guide ion beam tandem mass spectrometer will be used to gather the data.The data measured in this project are important for determining catalytic reaction mechanisms and for mapping out reaction paths. The clusters under study here are models for catalytic systems because they mimic small metal crystallites that comprise the reaction centers in catalysts used in industrial processes. Gas phase clusters themselves can also act as catalysts, as in the oxidation of carbon monoxide to carbon dioxide by platinum cluster anions.