Liquid-phase oxidation of tetralin in the presence of heterogeneous catalysts

Abstract

A STUDY Of heterogeneous catalysts in liquid-phase oxidation of hydrocarbons has recently at tracted increasing attention [1-3]. This interest is due to special features of the effect of the heterogeneous surface on the process as a whole and to a somewhat (in many cases) different distribution of reaction products. Typical heterogeneous catalysts of gaseous oxidation of hydrocarbons--transition metal oxides (IV and V periods) [4, 5]--were examined in most detail. Two points of view are now dealt with in the literature which are based on these investigations and concern the role of heterogeneous catalysts in liquidphase oxidation. According to the first, heterogeneous catalysts only initiate the process [2, 6]. Oi1 the other hand, it was found in many studies that in addition to the initiating effect, heterogeneous catalysts have a considerable influence on the distribution of reaction products [1, 7, 8]. This study deals with liquid-phase oxidation of tetralin in the presence of heterogeneous systems representing bivalent cobalt ions applied on zeolites, activated charcoal and silica gel. Cobalt oxide Co304 was also examined. Results obtained by oxidation of tetralin in heterogeneous catalysts were compared with results of non-catalytic oxidation and oxidation in the presence of cobalt stearate, a homogeneous catalyst.