Co3O4, CeO2 and Co3O4–CeO2 mixed oxides with Co/Ce nominal atomic ratio 0.1:5, prepared by coprecipitation method with sodium carbonate, were tested in the oxidation of propene under lean condition and the catalyst stability was checked by performing three consecutive heating–cooling cycles. Characterization of the textural properties were performed by surface area measurement BET, X-ray diffraction (XRD) and scanning electron microscopy (SEM) measurements. Among the Co3O4–CeO2 mixed oxides, Co3O4 (30 wt%)–CeO2 (70 wt%) gives the best activity attaining full propene conversion at 250 °C. This sample is characterized by the presence of Co3O4 particles well dispersed and in good contact with ceria according to BET and XRD data and as evidenced by SEM micrographs. Oxygen temperature-programmed desorption (O2 -TPD) and C3H6 -temperature-programmed reduction (C3H6-TPR) experiments were carried out in order to study the surface and bulk oxygen mobility and to correlate it to the activity. At temperature around 200 °C, O2-TPD experiments showed the desorption of mobile surface oxygen species for the most active samples, Co3O4 and Co3O4 (30 wt%)– CeO2 (70 wt%). C3H6-TPR experiments for both of the oxides also evidenced a high reactivity at low temperature, especially, for Co3O4 (30 wt%)– CeO2 (70 wt%) giving at 345 °C an intense peak of CO2 formation. Conversely, the ceria sample showed by C3H6-TPR much less pronounced oxygen bulk mobility, starting to react with propene above 500 °C and forming only CO. In this case, the catalytic activity of ceria was explained in terms of formation of surface oxygen vacancies which are relevant to the propene oxidation in presence of gaseous oxygen.

Liotta, L., Ousmane, M., Di Carlo, G., Pantaleo, G., Deganello, G., Marcì, G., et al. (2008). Total oxidation of propene at low temperature over Co3O4-CeO2 mixed oxides: Role of surface oxygen vacancies and bulk oxygen mobility in the catalytic activity. APPLIED CATALYSIS A: GENERAL, 347, 81-88 [10.1016/j.apcata.2008.05.038].

Total oxidation of propene at low temperature over Co3O4-CeO2 mixed oxides: Role of surface oxygen vacancies and bulk oxygen mobility in the catalytic activity

DEGANELLO, Giulio;MARCI', Giuseppe;
2008-01-01

Abstract

Co3O4, CeO2 and Co3O4–CeO2 mixed oxides with Co/Ce nominal atomic ratio 0.1:5, prepared by coprecipitation method with sodium carbonate, were tested in the oxidation of propene under lean condition and the catalyst stability was checked by performing three consecutive heating–cooling cycles. Characterization of the textural properties were performed by surface area measurement BET, X-ray diffraction (XRD) and scanning electron microscopy (SEM) measurements. Among the Co3O4–CeO2 mixed oxides, Co3O4 (30 wt%)–CeO2 (70 wt%) gives the best activity attaining full propene conversion at 250 °C. This sample is characterized by the presence of Co3O4 particles well dispersed and in good contact with ceria according to BET and XRD data and as evidenced by SEM micrographs. Oxygen temperature-programmed desorption (O2 -TPD) and C3H6 -temperature-programmed reduction (C3H6-TPR) experiments were carried out in order to study the surface and bulk oxygen mobility and to correlate it to the activity. At temperature around 200 °C, O2-TPD experiments showed the desorption of mobile surface oxygen species for the most active samples, Co3O4 and Co3O4 (30 wt%)– CeO2 (70 wt%). C3H6-TPR experiments for both of the oxides also evidenced a high reactivity at low temperature, especially, for Co3O4 (30 wt%)– CeO2 (70 wt%) giving at 345 °C an intense peak of CO2 formation. Conversely, the ceria sample showed by C3H6-TPR much less pronounced oxygen bulk mobility, starting to react with propene above 500 °C and forming only CO. In this case, the catalytic activity of ceria was explained in terms of formation of surface oxygen vacancies which are relevant to the propene oxidation in presence of gaseous oxygen.
2008
Liotta, L., Ousmane, M., Di Carlo, G., Pantaleo, G., Deganello, G., Marcì, G., et al. (2008). Total oxidation of propene at low temperature over Co3O4-CeO2 mixed oxides: Role of surface oxygen vacancies and bulk oxygen mobility in the catalytic activity. APPLIED CATALYSIS A: GENERAL, 347, 81-88 [10.1016/j.apcata.2008.05.038].
File in questo prodotto:
File Dimensione Formato  
Liotta-L.F._2008_Appl-Catal-A-Gen.pdf

accesso aperto

Dimensione 1.09 MB
Formato Adobe PDF
1.09 MB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10447/48162
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 251
  • ???jsp.display-item.citation.isi??? 244
social impact