Catalytic wet air oxidation of methylamine over supported manganese dioxide catalysts

• Manganese-based catalysts supported on various oxides were prepared by impregnation.
• Supported β-MnO2 catalysts were highly active in the CWAO of methylamine at 190 °C.
• Formate and ammonium ions were primary products in the CWAO of methylamine.
• Formate ions were totally mineralized while ammonium ions appeared to be refractory.
• Catalysts were shown to be chemically stable under the applied reaction conditions.

Catalytic formulations based on manganese oxides supported on inorganic oxides were developed for the treatment of methylamine-containing aqueous effluents via catalytic wet air oxidation (CWAO). Under the applied reaction conditions (190 °C, 50 bar total pressure) in the presence of heterogeneous β-MnO2-supported catalysts, formate and ammonium ions were detected as primary products. As the reaction proceeded, a complete mineralization of formate ions was observed while ammonium ions accumulated in the reaction media. The catalytic formulations elaborated in this work were shown to be stable under the applied reaction conditions without any significant leaching of the active phase.

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