Preparation of porous MnO2/CeO2 composite for the effective removal of formaldehyde from air

A porous MnO2/CeO2 composite catalyst was prepared via the template method for the catalytic decomposition of formaldehyde (HCHO). The physical and chemical properties of the catalysts were intensively characterized via X-ray diffraction, transmission electron microscopy, Brunauer-Emmett-Teller analysis, temperature programmed reduction system and X-ray photoelectron spectroscopy. The catalytic activity and stability for HCHO oxidation were measured via a fixed bed reactor, and the effects of physical and chemical properties of the catalysts on their catalytic performance were investigated. The results showed that the porous MnO2/CeO2 catalyst had abundant 3D pore structures, a large specific surface area, an amorphous structure, and an abundance of lattice oxygen species. Thus, the MnO2/CeO2 catalyst had high catalytic activity and stability for HCHO decomposition. This catalyst completely decomposed HCHO at 90 degrees C and maintained a 99% HCHO conversion rate over 72 h. The highly porous structure reduced the diffusion resistance in the reaction process and improved the efficiency of catalytic decomposition of HCHO. Doping with CeO2 improved the low temperature oxidation activity and catalytic stability of the porous MnO2/CeO2 catalyst. The porous MnO2/CeO2 composite was an effective agent for the removal of harmful HCHO from the air.