Different catalytic tests were carried out in a tubular Pd-membrane reactor feeding a reformer outlet type stream with a molar composition of 40% H2, 40% H2O, 12% CO2 and 8% CO. They were performed between 673 and 723 K and at pressures ranging from 100 kPa to 800 kPa. At 723 K and 800 kPa, the CO conversion and H2 recovery values were 96% and 88%, respectively. A stability test including several start-up and shut-down cycles showed high stability of the Pt(0.1) catalyst.Pt(wt%)/La2O3(27)·SiO2 catalysts with wt% = 0.02 up to 1.2 were synthesized and tested in a conventional fixed-bed reactor. In differential mode, the Pt(0.1)/La2O3(27)·SiO2 catalyst showed higher activity per gram of Pt than the other solids. XPS showed the presence of only surface metallic platinum, in both the fresh and used Pt(0.1 wt%) formulation, which could be responsible for the high catalytic activity. At higher Pt loads both Ptδ+ and Pt° species were present at the surface. The presence of La2Si2O7 in all solids was detected by XRD. Graphitic carbon in the used catalysts was not detected through laser Raman spectroscopy.
|Titolo:||Optimal Pt load of a Pt/La2O3·SiO2 highly selective WGS catalyst used in a Pd-membrane reactor|
|Data di pubblicazione:||2014|
|Appare nelle tipologie:||1.1 Articolo in rivista|