Photothermal Synergistic Effect of M/Tio2 Nanofiber Catalysts Prepared by Electrospinning in Removing Vocs

Abstract

In this work, a series of M/TiO2 (M= Cu, Mn, Co, Ni) nanofiber catalysts were prepared by electrospinning technology, and their photothermal synergism on toluene oxidation was investigated. The sequence in catalytic activity for the oxidation of toluene was Cu/TiO2 > Mn/TiO2 > TiO2 > Co/TiO2 > Ni/TiO2. The excellent catalytic performance of Cu/TiO2 came from its good low-temperature reducibility and lattice oxygen mobility. The good O2 activation ability was the reason why Cu/TiO2 had the best promotional effect of light irradiation. In situ DRIFTS was conducted by switching the feed gas. The results revealed that the adsorbed oxygen species had a promoting effect on the generation of benzaldehyde, while the lattice oxygen mainly promoted the decomposition of benzaldehyde. The decomposition of benzaldehyde was the rate-controlling step of the catalytic oxidation of toluene. The reaction pathway of catalytic oxidation of toluene on Cu/TiO2 was as follows: toluene was first gradually oxidized to benzyloxy group, benzaldehyde and benzoic acid, and finally converted to CO2 and H2O. For the photothermal catalysis, the photoelectrons could reduce O2 to •O2-, further oxidizing toluene to CO2 and H2O.

Keywords: Photothermal catalysis, electrospinning technology, reaction mechanism, nanofibers, redox properties