Study of catalysts and mechanisms in synthesis reactions. Final report

摘要

During the catalytic oxidation of hydrocarbons over many metal oxides, radicals are formed on the surface and these intermediates emanate into the gas phase where they become involved in homogeneous reactions. Examples include methyl radicals formed during the oxidative coupling of methane, allyl radicals formed during the partial oxidation of propylene and hydroxyl radicals formed during the reaction of water with molecular oxygen. Higher temperatures (> 600 deg C) generally favor radical formation. Other factors that effect radical formation, as well as secondary reactions of the radicals with surfaces have been investigated. A matrix isolation electron spin resonance (MIESR) system and a laser-induced fluorescence (LIF) system have been used to study hydrocarbon and hydroxyl radicals, respectively. The goal of the research is to understand the role that these surface generated intermediates play in catalytic reactions, with emphasis on the partial and complete oxidation of hydrocarbons. The results will find application in the utilization of natural gas reserves in an efficient and nonpolluting manner.