Oxidation of Ethylbenzene Catalyzed by NHPI Combined with Cobalt Sulfonated Phthalocyanine

An efficient and mild method to convert ethylbenzene into the corresponding oxides,catalyzed by a combined catalytic system consisting of N-hydroxyphthalimide(NHPI) and cobalt sulfonated phthalocyanine(CoSPc) was developed.Experimental results showed that the reaction conditions of controlling the molar ratio of NHPI and ethylbenzene to be 0.050,the molar ratio of NHPI and CoSPc to be 6 and reaction temperature to be 90 ℃ were the most favorable,under which the conversion rate of ethylbenzene and the selectivity of acetophenone reached 82.4% and 79.1% after 10 h of reaction in oxygen atmosphere.The conversion rate increased as prolonging reaction time,it reached 99.0% after 15 h of reaction.However,when air was used instead of oxygen without other conditions changed,the conversion rate dropped to 64.0%.In addition,the synergistic effect of NHPI and CoSPc was approved by comparing experiments,and cocatalytic activities of CoCl2,Co(AcO)2,CoPc and CoSPc were compared also,results indicated that the most efficient cocatalyst was CoSPc.