Data di Pubblicazione:
2015
Citazione:
Total oxidation of formaldehyde over MnOx-CeO2 Catalysts : the effect of acid treatment / J. Quiroz, J. Giraudon, A. Gervasini, C. Dujardin, C. Lancelot, M. Trentesaux, J. Lamonier. - In: ACS CATALYSIS. - ISSN 2155-5435. - 5:4(2015), pp. 2260-2269. [10.1021/cs501879j]
Abstract:
The effect of acid treatment in mixed MnOx−CeO2 samples has
been investigated in the catalytic total oxidation of formaldehyde. The acid
treatment has no effect on the textural and redox properties of the materials when
Mn is stabilized in a MnOx−CeO2 solid solution (Mn content below 50%).
However, these properties were found to be highly altered by acid treatment
when the solubility limit of Mn in the ceria was exceeded (Mn content above
50%). This enabled access to the primary porosity and oxidized the manganese
species to a higher oxidation state via a Mn dismutation reaction. As a result, the
catalytic activity of pure manganese oxide, after chemical activation, in the
oxidation of formaldehyde is greatly improvedat 100 °C, the conversion of
formaldehyde is increased by a factor of 5 and the corresponding intrinsic
reaction rate by 1.4. Combined in situ surface analysis unambiguously identified
formate species as a result of formaldehyde oxidation at room temperature on the
chemically activated pure MnOx. The evolution of various surface species was
monitored by increasing the temperature and in situ FTIR, and XPS results provided direct evidence of the desorption of
monodentate formate species into formaldehyde and the oxidation of bidentate-bridging formate species. Changes in the average
oxidation state of surface manganese confirmed the participation of oxygen from MnOx in the formation of formate species at
room temperature and their transformation into CO2 and H2O when increasing the temperature.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
formaldehyde; catalytic oxidation; volatile organic compound (VOC); MnOx−CeO2 mixed oxides; chemical activation;
indoor pollution
Elenco autori:
J. Quiroz, J. Giraudon, A. Gervasini, C. Dujardin, C. Lancelot, M. Trentesaux, J. Lamonier
Link alla scheda completa: