The Reactivity of Ozone on Transition Metal Oxide Catalysts

臭氧在过渡金属氧化物催化剂上的反应活性

• 批准号: 9311876
• 负责人: S. Ted Oyama
• 金额: $ 25万
• 依托单位: Virginia Polytechnic Institute and State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-07-01 至 1998-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9311876&HistoricalAwards=false
• 关键词: Reactivity; Ozone; Transition; Metal; Oxide

9311876 Oyama This is a study of the reactions of ozone on transition-metal oxides. Ozone decomposition on oxide catalysts is observed to determine the effects of oxide-support and oxide-oxide interactions; kinetics measurements are made for the most active systems. Adsorption/desorption properties of the oxides are studied using temperature-programmed techniques; the mode of ozone adsorption is studied using isotope scrambling. Dispersion, phase composition, and surface intermediates in single-component and binary catalytic systems are determined using X-ray diffraction and laser Raman spectroscopy. In situ techniques such as the Hall effect, quartz-crystal microbalance, and surface charge measurements are employed to show whether p-type oxides are more active catalysts and whether the superoxide ion (02-) is a possible reaction intermediate. Finally, the reactivities of ozmne/oxygen mixtures with ethanol or propylene are observed. It is "common knowledge" that transition-metal oxides can catalyze reactions and decomposition of ozone, but these systems have never been studied systematically. This study has not only fundamental significance, but also practical importance both in issues about the environmental fate of ozone and in the development of technology to control ozone levels in environmental or occupational settings. ***

9311876 Oyama这是一项关于臭氧在过渡金属氧化物上的反应的研究。观察氧化物催化剂上的臭氧分解，以确定氧化物-载体和氧化物-氧化物相互作用的影响；对最活跃的体系进行动力学测量。用程序升温技术研究了氧化物的吸附/脱附性质；用同位素扰乱法研究了臭氧的吸附模式。用X射线衍射和激光拉曼光谱测定了单组分和二元催化体系的分散度、物相组成和表面中间体。利用霍尔效应、石英晶体微天平和表面电荷测量等原位技术研究了p型氧化物是否是活性更高的催化剂以及超氧离子(02-)是否是可能的反应中间体。最后，观察了臭氧/氧混合物与乙醇或丙烯的反应活性。过渡金属氧化物可以催化臭氧的反应和分解是众所周知的，但这些体系从未被系统地研究过。这项研究不仅具有基本的意义，而且在臭氧的环境命运问题上以及在环境或职业环境中控制臭氧水平的技术开发方面都具有实际意义。***