title: Enhanced effect of water vapor on complete oxidation of formaldehyde in air with ozone over MnOx catalysts at room temperature.
abstract: At room temperature, the enhanced effect of water vapor on ozone catalytic oxidation (OZCO) of formaldehyde to CO2 over MnOx catalysts and the reaction stability was reported. In a dry air stream, only below 20% of formaldehyde could be oxidized into CO2 by O3. In humid air streams (RH≥55%), ∼100% of formaldehyde were oxidized into CO2 by O3 and the reaction stability was significantly enhanced. Meanwhile, in situ Diffuse Reflectance Infrared Fourier Transform (DRIFT) spectra of OZCO of HCHO demonstrate that the amount of both monodentate and bidentate carbonate species on MnOx, in the dry stream, increased gradually with time on stream (TOS). However, in the humid stream, almost no accumulation of carbonate species on the catalysts was observed. To clarify the enhanced mechanism, formaldehyde surface reactions and CO2 adsorption/desorption on the fresh, O3 and O3+H2O treated MnOx catalysts were examined comparatively.
authors.affiliation: Laboratory of Plasma Physical Chemistry, School of Physics and Optoelectronic Engineering & School of Chemistry, Dalian University of Technology, Dalian 116024, China.
authors.forename: De-Zhi
authors.initials: DZ
authors.lastname: Zhao
authors.forename: Chuan
authors.initials: C
authors.lastname: Shi
authors.forename: Xiao-Song
authors.initials: XS
authors.lastname: Li
authors.forename: Ai-Min
authors.initials: AM
authors.lastname: Zhu
authors.forename: Ben W-L
authors.initials: BW
authors.lastname: Jang
mesh_terms: D000327:Adsorption; D000393:Air Pollutants / Q000737:chemistry*; D016902:Air Pollution, Indoor; D002245:Carbon Dioxide / Q000737:chemistry; D002384:Catalysis; D005557:Formaldehyde / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry; D017895:Manganese Compounds / Q000737:chemistry*; D016877:Oxidants / Q000737:chemistry; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D010126:Ozone / Q000737:chemistry*; D013227:Steam; D013696:Temperature
chemical_list: D000393:Air Pollutants; D017895:Manganese Compounds; D016877:Oxidants; D010087:Oxides; D013227:Steam; D002245:Carbon Dioxide; D005557:Formaldehyde; C027424:manganese oxide; D010126:Ozone; D006861:Hydrogen Peroxide