Preparation and catalytic properties of Cu2O–CoO/Al2O3 composite coating prepared on aluminum plate by microarc oxidation

In order to develop a catalyst with a high activity and stability for the catalytic wet peroxide oxidation (CWPO) process under ambient conditions, A Cu2O–CoO/Al2O3 composite coating was prepared on an aluminium substrate by microarc oxidation in a phosphate electrolyte modified with Cu(Ac)2 and Co(Ac)2 solutions. Microstructure, phase and chemical composition of the coating were characterized by SEM, XRD and XPS, respectively. The Al-supported Cu2O–CoO/Al2O3 composite coating exhibited excellent catalytic activities for CWPO of methyl orange under ambient conditions. The degradation efficiency of methyl orange was 99.8% at 25 °C for 12 h, or 100% at 65 °C for 90 min. The catalyst exhibited an excellent chemical stability with negligible leaching ions. It could be recycled without any time-consuming filter operation and regenerated by ultrasonic vibrating washing.