Ozone catalytic oxidation of toluene over 13X zeolite supported metal oxides and the effect of moisture on the catalytic process
| Autor: | C. Ramakrishna, S. Chandra Shekar, T. Gopi, Racharla Krishna, G. Swetha, Bijendra Saini, P.V.L. Rao |
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| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Ozone
Chemistry(all) Thermal desorption spectroscopy General Chemical Engineering Inorganic chemistry 02 engineering and technology 010402 general chemistry 01 natural sciences Catalysis lcsh:Chemistry chemistry.chemical_compound 13X zeolite Benzene GeneralLiterature_REFERENCE(e.g. dictionaries encyclopedias glossaries) ComputingMilieux_MISCELLANEOUS Moisture Chemistry General Chemistry Catalytic oxidation 021001 nanoscience & nanotechnology Toluene Toluene oxidation 0104 chemical sciences lcsh:QD1-999 Chemical Engineering(all) 0210 nano-technology |
| Zdroj: | Arabian Journal of Chemistry, Vol 12, Iss 8, Pp 4502-4513 (2019) |
| ISSN: | 1878-5352 |
| Popis: | This paper reports the behavior of 13X zeolite supported Ce, Cu, Co, Ag and Mn metal oxides toward ozone catalytic oxidation (OZCO) of toluene and the influence of moisture on the decomposition process. The simple impregnation method was adapted to disperse the metal oxides and found highly active for toluene oxidation in the presence of ozone. The steady-state activities and ozone decomposition data reveal that the activity is in the order of Mn/13X > Ce/13X > Cu/13X > Ag/13X > Co/13X and Mn/13X > Cu/13X > Ce/13X > Ag/13X > Co/13X, respectively. The extent of ozone decomposition is responsible for the degree of oxidative decomposition of toluene over the Mn/13X catalyst. The addition of moisture (Relative Humidity of 25%) to the reaction mixture considerably enhanced the conversion of toluene and selectivity to carbon oxides from 49% to 61% and 38% to 53% respectively, on the Mn/13X catalyst. The two sets of experiment results reveal that the surface adsorbed by-products such as benzene, benzaldehyde, p-methyl phenol and oxalic acid are considerably oxidized to CO2 in the presence of moisture whereas in the absence of moisture these by-products are slowly oxidized. The activity data in the presence of ozone and moisture also reveal that the moisture has considerably enhanced the activation of surface adsorbed by-products than that of initial toluene oxidation. Based on the temperature programmed desorption and temperature programmed oxidation studies, the addition of moisture decreased the by-products accumulation thereby, reduced the catalyst deactivation and enhanced the extended oxidation of toluene on the Mn/13X zeolite. Keywords: 13X zeolite, Ozone, Catalytic oxidation, Toluene, Moisture |
| Databáze: | OpenAIRE |
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