抄録
This study was aimed at examining a reaction course of the malonic acid by the sonophotocatalysis. Malonic acid and succinic acid were prepared as nonvolatile organic compounds. Argon atmosphere was served in all cases. Supplied ultrasound was 200 kHz and 200 W. Illumination source was 500 W-Xe lamp. Each compound was dissolved into water (10mM). In the case of malonic acid, formic acid, oxalic acid, carbon CO_2 and CO were obtained under sonication. On the other hand, acetic acid, CO_2 and CH_4 were obtained under photocatalysis. Methane, in latter case, would be produced from acetic acid. Thus, a breakdown in molecule proceeds under sonication and a decarboxylation proceeds step by step under photocatalysis. Synergistic effects were obtained in the sonophotocatalytic system. For example, the rate of production of CO increased over seven times as much as sum of rates of both systems. In the case of succinic acid solution, fumaric acid and maleic acid were detected during sonolysis. This means a double-bond forming reaction and the elimination reaction of hydrogen occur under sonication. As fumalic acid is trans type and stable compound, obtained amount of this material was larger than maleic acid, which was cis type compound.
