Catalysis in liquid-phase autoxidation: III. Comparison of metal oxide versus polymeric surfaces

Abstract

The rate of oxidation of tetralin in a solution of chlorobenzene was measured in the presence of metal oxide and supported metal oxide catalysts at 65 to 115 °C at conditions identical to those previously employed with polymeric catalysts. At 90 °C the specific activity of polymeric catalysts is higher than that of the metal oxide catalysts tested with the exception of copper oxide. Metal oxide catalysts also exhibited a lower apparent activation energy than poly(tetrafluoroethylene). Supporting the metal oxides on a high area substrate failed to increase their activity. The activity of the metal oxide catalysts for the decomposition of tetralin hydroperoxide in chlorobenzene under N 2 was also determined. Relative catalytic activity for the decomposition of tetralin hydroperoxide paralleled that observed for the oxidation of tetralin, and suggests that a major role of the catalyst is to accelerate radical production via the decomposition of tetralin hydroperoxide.