Abstract
Formaldehyde (HCHO) is known as a harmful gas which causes sick house syndrome. Manganese dioxide (MnO2) is practically used for a major ingredient of air cleaning materials, because it reacts with harmful HCHO to give stoichiometrical carbon dioxide (CO2) even at room temperature. Although MnO2 can form various kinds of polymorph, effect of the crystal form has not been yet investigated on the removal efficiency for HCHO. Therefore this study aims to correlate physical and chemical properties of MnO2 samples on the oxidative decomposition of HCHO for the further development of air cleaning materials with higher performance. Authors tested removal and oxidative decomposition performance of HCHO gas using a breakthrough test and mass balance test. The results showed crystal form of manganese dioxide affected on the removal performance of HCHO in the following order: γ>α=ε. On the other hand, significant effect was not found for conversion to CO2.
