Gold catalysts on mechanochemically prepared mixed ceria supports doped with FeO x and MnO x were studied in the reaction of preferential oxidation of CO in H 2 rich stream (PROX) in the presence of 20% CO 2 and 10% H 2O. The average size and the size distribution of gold particles were estimated by HRTEM. By means of XPS the Au XPS states at various binding energies, assigned to differently charged Au nanopar-ticles, were distinguished. The catalytic activity and selectivity in the oxidation of CO in dry H 2-reach stream was high, however the PROX activity was significantly suppressed by the addition of high concentrations of water and CO 2. The two step calcinations of catalysts, first at 400°C and then at 550°C, showed no better performance in PROX reaction carried out at realistic experimental conditions. However, after the two-step calcination procedure, nanosized gold particles of high thermal stability were obtained over MnO x doped ceria. © 2011 Elsevier B.V. All rights reserved.
Preferential oxidation of CO in H2 rich stream (PROX) over gold catalysts supported on doped ceria: effect of water and CO2
G Pantaleo;
2011
Abstract
Gold catalysts on mechanochemically prepared mixed ceria supports doped with FeO x and MnO x were studied in the reaction of preferential oxidation of CO in H 2 rich stream (PROX) in the presence of 20% CO 2 and 10% H 2O. The average size and the size distribution of gold particles were estimated by HRTEM. By means of XPS the Au XPS states at various binding energies, assigned to differently charged Au nanopar-ticles, were distinguished. The catalytic activity and selectivity in the oxidation of CO in dry H 2-reach stream was high, however the PROX activity was significantly suppressed by the addition of high concentrations of water and CO 2. The two step calcinations of catalysts, first at 400°C and then at 550°C, showed no better performance in PROX reaction carried out at realistic experimental conditions. However, after the two-step calcination procedure, nanosized gold particles of high thermal stability were obtained over MnO x doped ceria. © 2011 Elsevier B.V. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
