Acetone Oxidation Using Ozone on Manganese Oxide Catalysts

Abstract

Supported manganese oxide catalysts were prepared by the impregnation of alumina foam blocks washcoated with alumina and silica. The manganese content based on the weight of the washcoats was 10 wt % calculated as MnO2. Fourier transform profiles of the Mn K-edge EXAFS spectra for these samples gave three distinctive peaks at 0.15, 0.25, and 0.32 nm and were close to the profiles of Mn3O4 and beta-MnO2. The number of surface active sites was determined through oxygen chemisorption measurements at a reduction temperature (Tred = 443 K) obtained from temperature-programmed reduction (TPR) experiments. Acetone catalytic oxidation was studied from room temperature to 573 K, and was found to be highly accelerated by the use of ozone on both catalysts with substantial reductions in the reaction temperature. The only carbon-containing product detected was CO2. The alumina-supported catalyst was found to be more active than the silica-supported catalyst in acetone and ozone conversion, with higher turnover frequencies (TOFs) for both reactions. The pressure drop through the foam was low and increased little (0.003 kPa/10 000 h(-1)) with space velocity. In situ steady-state Raman spectroscopy measurements during the acetone catalytic oxidation reaction showed the presence of an adsorbed acetone species with a C-H bond at 2930 cm(-1) and a peroxide species derived from ozone with an O-O bond at 890 cm(-1).

Facile Preparation of an Excellent Pt/RuO2‐MnO2/CNTs Nanocatalyst for Anodes of Direct Methanol Fuel Cells

“…For the XRD patterns of RuO 2 -MnO 2 /CNTs, as shown in Figure 3, only a few broad peaks with less intensity at around 2h = 18.1/ and 37.0/, attributed to MnO 2 (200) and MnO 2 (400) [29,31] [32][33][34]. As to the RuO 2 / CNTs, the main peak is at 75°C, which attributes to the reduction of most RuO 2 to Ru.…”

Relationship Between the Structure of Manganese Oxides on Alumina and Catalytic Activities for Benzene Oxidation with Ozone

“…It has been reported that ozone decomposed to O 2 on supported manganese oxide catalysts as expressed by Eqs. (1-3), where * denotes active sites on the catalyst [11,21,22].…”

Novel mechanistic view of catalytic ozonation of gaseous toluene by dual-site kinetic modelling

“…Although numerous studies were conducted on the catalytic ozonation of VOCs [16][17][18][19][20][21][22][23], the underlying mechanism and its relevant kinetic steps remain unclear [24]. Other than the recent study by Rezaei and Soltan [24], no studies were performed to test the validity of the L-H s mechanism on the catalytic ozonation of toluene over alumina-supported manganese oxide catalysts.…”