Résumé
In this work, the activity of bimetallic Pd-Au doped hierarchically structured titania catalysts has been investigated in the total oxidation of toluene. In earlier works, doping titania with group Vb metal oxides ensured an increased catalytic performance in the elimination of VOC molecules. A synergy between gold and palladium loaded at the surface of titania supports provided better performances in VOC oxidation reactions. Therefore, the main focus in this work was to investigate the durability of the prepared catalysts under long time-on-stream periods. Vanadium-doped catalysts showed a stable activity throughout the whole 110 h test, whereas, surprisingly, niobium-doped catalysts presented a cycle-like activity while nevertheless maintaining a high performance in toluene elimination. Operando Diffuse Reflectance Infrared Fourrier Transform spectroscopy (DRIFT) experiments revealed that variations in the presence of OH radicals and the presence of carbonaceous compounds adsorbed at the surface of spent catalysts varies with the occurrence of oscillations. X-ray Photoelectron Spectroscopy (XPS) results show that interactions between the material and the active phase provided extra amounts of mobile oxygen species and participated in easing the reduction of palladium. An enhanced redox reaction scheme is thus obtained and allows the occurrence of the cyclic-like performance of the catalyst.
| langue originale | Anglais |
|---|---|
| Numéro d'article | 574 |
| Nombre de pages | 11 |
| journal | Catalysts |
| Volume | 8 |
| Numéro de publication | 12 |
| Les DOIs | |
| état | Publié - 1 déc. 2018 |
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Oscillatory behavior of Pd-Au catalysts in toluene total oxidation. / Barakat, Tarek; Rooke, Joanna C.; Chlala, Dayan; Cousin, Renaud; Lamonier, Jean François; Giraudon, Jean Marc; Casale, Sandra; Massiani, Pascale; Su, Bao Lian; Siffert, Stéphane.
Dans: Catalysts, Vol 8, Numéro 12, 574, 01.12.2018.Résultats de recherche: Contribution à un journal/une revue › Article
TY - JOUR
T1 - Oscillatory behavior of Pd-Au catalysts in toluene total oxidation
AU - Barakat, Tarek
AU - Rooke, Joanna C.
AU - Chlala, Dayan
AU - Cousin, Renaud
AU - Lamonier, Jean François
AU - Giraudon, Jean Marc
AU - Casale, Sandra
AU - Massiani, Pascale
AU - Su, Bao Lian
AU - Siffert, Stéphane
PY - 2018/12/1
Y1 - 2018/12/1
N2 - In this work, the activity of bimetallic Pd-Au doped hierarchically structured titania catalysts has been investigated in the total oxidation of toluene. In earlier works, doping titania with group Vb metal oxides ensured an increased catalytic performance in the elimination of VOC molecules. A synergy between gold and palladium loaded at the surface of titania supports provided better performances in VOC oxidation reactions. Therefore, the main focus in this work was to investigate the durability of the prepared catalysts under long time-on-stream periods. Vanadium-doped catalysts showed a stable activity throughout the whole 110 h test, whereas, surprisingly, niobium-doped catalysts presented a cycle-like activity while nevertheless maintaining a high performance in toluene elimination. Operando Diffuse Reflectance Infrared Fourrier Transform spectroscopy (DRIFT) experiments revealed that variations in the presence of OH radicals and the presence of carbonaceous compounds adsorbed at the surface of spent catalysts varies with the occurrence of oscillations. X-ray Photoelectron Spectroscopy (XPS) results show that interactions between the material and the active phase provided extra amounts of mobile oxygen species and participated in easing the reduction of palladium. An enhanced redox reaction scheme is thus obtained and allows the occurrence of the cyclic-like performance of the catalyst.
AB - In this work, the activity of bimetallic Pd-Au doped hierarchically structured titania catalysts has been investigated in the total oxidation of toluene. In earlier works, doping titania with group Vb metal oxides ensured an increased catalytic performance in the elimination of VOC molecules. A synergy between gold and palladium loaded at the surface of titania supports provided better performances in VOC oxidation reactions. Therefore, the main focus in this work was to investigate the durability of the prepared catalysts under long time-on-stream periods. Vanadium-doped catalysts showed a stable activity throughout the whole 110 h test, whereas, surprisingly, niobium-doped catalysts presented a cycle-like activity while nevertheless maintaining a high performance in toluene elimination. Operando Diffuse Reflectance Infrared Fourrier Transform spectroscopy (DRIFT) experiments revealed that variations in the presence of OH radicals and the presence of carbonaceous compounds adsorbed at the surface of spent catalysts varies with the occurrence of oscillations. X-ray Photoelectron Spectroscopy (XPS) results show that interactions between the material and the active phase provided extra amounts of mobile oxygen species and participated in easing the reduction of palladium. An enhanced redox reaction scheme is thus obtained and allows the occurrence of the cyclic-like performance of the catalyst.
KW - Bimetallic catalysts
KW - Doping
KW - Gold
KW - Hierarchically porous
KW - Oscillatory behavior
KW - Palladium
KW - Titania
KW - VOC oxidation
UR - http://www.scopus.com/inward/record.url?scp=85057426790&partnerID=8YFLogxK
U2 - 10.3390/catal8120574
DO - 10.3390/catal8120574
M3 - Article
AN - SCOPUS:85057426790
VL - 8
JO - Catalysts
JF - Catalysts
SN - 2073-4344
IS - 12
M1 - 574
ER -