Parial Oxidation of Aromatics with Activated-Oxygen Cell Reactions

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One step synthesis of phenol from benzene with reductivated O2 over the cathode was a success by applying an H2 cell reaction system. Cathodes of some carbon materials activated woth HNO3 aq. at refluxing were active for the hydroxylation of benzene. The order of the cathodes for the yield of products was carbon whisker a10 carbon black >> active carbon > graphite.The co-addition of Pd black and Fe2O3 and the addition of CuSO 4 to carbon whisker enhanced the catalytic acticity of the cathode for the hydroxylation of benzene. Especially, the maximum yield of phenol was obtained during generating electricity at 0.3 V for the cathode of carbon whiskeradded CuSO4. This result demonstrates that the possibility of phenol and electroricity. The oxidation of toluene occurredwith our reaction system, producing o-, m-, p-cresols and benzaldehyde, benzyl alcohol. The selectiviy to cresols was high for the cathode of carbom black and active carbon, that to benzaldehyde and benzyl alcohol was high for the cathode of carbon whisker and graphite. The selectivities of the products can be controlled by changing the oncentration of the electrolyte solutions of H3PO4. Cresols were selectively produced (90%) at low concentration of H3PO4, and benzaldehyde was selectively produced (95%) at high concentration. The synergistic effect of active carbon and carbon whisker for the oxidation of toluene was observed. The catalytic activity for the cathode of the mixture of active carbon andcarbon whisker (1 : 1) was 6 tumes of that for active carbon alone and twice of that for carbon whisker alone. These observations could be explained by a Fenton-type chemistry assuming HO・ as an active oxugen.