Enhanced catalytic activity of metal salts of metal phthalocyanine tetracarboxylic acids in the autoxidation of thiophenol in hexane

Catalytic activities of metal (Fe3+, Co2+, Ni2+ and Cu2+ salts of metal (FeCl2+, Co2+, Ni2+ and Cu2+)) phthalocyanine tetracarboxylic acids dispersed on a carrier in the autoxidation of thiophenol have been investigated. Absorptions of O2 in the presence of the catalysts were measured. P values (percentages of the absorbed O2 after 30 min. per theoretical volume) and T values (absorbed O2 mol s−1 (cat. mol)−1/substrate mol l−1) at the original point were adopted to evaluate the catalytic activities. Fe3+ salt of cobalt phthalocyanine tetracarboxylic acid showed the highest activity. The mechanism of the activity was investigated electrochemically by using carbon paste electrodes containing the catalyst.