Study of manganese–cerium composite oxide catalysed oxidation for low concentration formaldehyde at room temperature

Catalytic oxidation at room temperature is a promising alternative approach for indoor formaldehyde elimination. However, the development of non-precious metal room temperature catalysts is still highly challenging. In this study, manganese-cerium composite oxides (MC) were developed and optimized. The removal performance of low concentrations of formaldehyde at room temperature was comprehensively evaluated. Formaldehyde removal was achieved with MC under dark at a level comparable to that of the commercial P25 catalyst. The removal efficiency of 90.9% in 24 h at room temperature was obtained for the initial formaldehyde concentration of 1.2 ± 0.1 ppm. Using electron paramagnetic resonance spectroscopy, free radicals were confirmed to play a key role in formaldehyde degradation on MC. Formate was detected as the main intermediate product by in situ DRIFTs, and the mechanism of MC catalytic oxidation at room temperature was deduced.