Catalytic oxidation of formaldehyde by MnCo3MOx catalyst: Effect of rare earth elements and temperature

The MnCo3MOx (M = Ce,La,Pr) composite catalysts were synthesized by co-precipitation method and tested for formaldehyde removal and carbon dioxide selectivity. The influence of the types of rare earth elements and molar ratio of Mn/Co/M was investigated. The addition of cerium improves the catalytic activity of MnCo3Ox. The catalyst could efficiently eliminate HCHO into CO2 and H2O when the molar ratio of Mn/Co/Ce was 1/3/7.96% HCHO conversion was achieved at ambient temperature. The prepared samples were characterized by XRD, BET, H2-TPR and XPS techniques to explain the improvement of catalytic activity. The results show that a stable solid solution can be formed between CeO2 and MnCo3Ox, and the strong interaction promotes the reaction. The addition of Ce increases the specific surface area of the catalyst and enhances the reduction of MnCo3Ox and surface active oxygen, thereby increasing the catalytic activity for removing HCHO. This study provides a reference for the purification of indoor formaldehyde.