화학공학소재연구정보센터
Journal of Applied Electrochemistry, Vol.28, No.9, 873-880, 1998
Selective electrosynthesis of p-methoxybenzaldehyde at spinel type CoMn2O4/titanium-composite anodes
Activated titanium anodes with a spinel coating of CoMn2O4 of about 1 mu m thickness were developed. A relative stability in acid electrolytes was found. The novel anode was employed for the anodic oxidation of p-methoxytoluene (PMT) to p-methoxybenzaldehyde (PMB), which is of industrial interest, Batch type electrolyses with 30% theoretical conversion (4 F mol(-1)) were used for a parametric screening. The solvent/electrolyte-system was 1 M H2SO4/5 M H2O in methanol. Optimum results (60% selectivity, 50-60% current efficiency) were obtained at low concentrations of the educt (0.2 M), A part of the current is consumed for the formation of the benzylmethylether, which can be further oxidized to PMB, It was proved that the novel anode operates according to the mechanism of heterogeneous redox catalysis with ter- and heptavalent manganese as the redox species. A turnover factor of > 2000 is unusual for a spinel in acid solution.