The positive effect of water on acetaldehyde oxidation depended on the reaction temperature and MnO2 structure

The effect of H2O on acetaldehyde oxidation was studied and α-, γ-, δ-MnO2 can be affected by the H2O vapor, while β-MnO2 is hardly affected by the H2O vapor during acetaldehyde oxidation. The H2O vapor can facilitate the catalytic oxidation of acetaldehyde at moderate temperatures (ca. 70∼100 °C), with a negative effect observed at high temperatures (>100 °C). The stretching mode of the Mn−O−Mn chains in α-, γ-, δ-MnO2 allows the associatively...