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

A porous MnO 2 /CeO 2 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 MnO 2 /CeO 2 catalyst had abundant 3D pore structures, a large specific surface area, an amorphous structure, and an abundance of lattice oxygen species. Thus, the MnO 2 /CeO 2 catalyst had high catalytic activity and stability for HCHO decomposition. This catalyst completely decomposed HCHO at 90 °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 CeO 2 improved the low temperature oxidation activity and catalytic stability of the porous MnO 2 /CeO 2 catalyst. The porous MnO 2 /CeO 2 composite was an effective agent for the removal of harmful HCHO from the air.