The Reactivity of Ozone on Transition Metal Oxide Catalysts

9311876 Oyama这是一项关于臭氧与过渡金属氧化物反应的研究。观察臭氧在氧化物催化剂上的分解，以确定氧化物-载体和氧化物-氧化物相互作用的影响；动力学测量是针对最活跃的体系进行的。利用程序升温技术研究了氧化物的吸附/解吸特性；采用同位素置乱法研究了臭氧吸附模式。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中的分散、相组成和表面中间体。采用霍尔效应、石英晶体微天平和表面电荷测量等原位技术来显示p型氧化物是否是更活跃的催化剂，以及超氧化物离子（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性。过渡金属氧化物可以催化臭氧的反应和分解，这是“常识”，但这些系统从未被系统地研究过。这项研究不仅在臭氧的环境命运问题以及在环境或职业环境中控制臭氧水平的技术发展方面具有根本意义，而且具有实际意义。＊＊＊

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. ***