CO Oxidation over Cerium and Group 4 Metal Oxide Clusters

  CO oxidation by molecular oxygen is an important type of reaction.[1] Oxides of cerium (Ce) and group 4 metals (Ti,Zr,Hf) are widely used as both catalysts or catalytic supports for the CO oxidation.[2] To investigate the mechanistic details of the related metal oxides in the catalytic reactions,mass spectrometry and density functional theory (DFT) computations have been employed to study the reactions of CO with oxide clusters of Ce,Ti,Zr,and Hf.The experiments identified the following series of reactions under near room temperature conditions: (CeO2)nO– + CO → (CeO2)n – + CO2 (n=4–21) (1) (TiO2)nO– + CO → (TiO2)n – + CO2 (n=3–14) (2) (ZrO2)nO– + CO → (ZrO2)nOCO– (n=3–14) (3) (HfO2)nO– + CO → (HfO2)nOCO– (n=2–13) (4) In addition,the reaction rate constants of (CeO2)nO– with CO strongly depend on the cluster size n.The DFT results are in agreement with the experiments and interesting electronic structures and energetics for CO oxidation over cerium and group 4 metal oxide clusters have been revealed.Based on the cluster chemistry,a catalytic mechanism is proposed to rationalize a fundamental difference between reducible and irreducible metal oxide supports in the CO oxidation.[3]

作者单位: Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190
母体文献: 中国科学院“百人学者论坛”2011学术研讨会论文集
会议名称: 中国科学院“百人学者论坛”2011学术研讨会
会议时间: 2011年7月1日
会议地点: 北京
主办单位: 中科院
语 种: eng
在线出版日期: 3000年1月1日