CATALIZADORES DE Pt Y Rh SOBRE La2O3 PARA LA PRODUCCIÓN DE HIDRÓGENO EN UN REACTOR DE MEMBRANA

JOHN F. MÚNERA, LAURA M. CORNAGLIA, SILVIA IRUSTA, EDUARDO A. LOMBARDO

Villa Giardino-Córdoba-Argentina

Congreso; XIII CONGRESO ARGENTINO DE CATÁLISIS Y 2do CONGRESO MERCOSUR DE CATÁLISIS; 2003

The catalytic production of hydrogen through the carbon dioxide reforming of methane was carried out   in a dense Pd/Ag membrane reactor. The effect of  pressure  and  the sweep gas flow  over  conversion and  hydrogen production was  studied. The best results were obtained operating  at atmospheric pressure with   high W/F values and a sweep gas flow rate of  30 ml min-1. The activity and stability of Pt/La2O3  were investigated and compared to the Rh/La2O3 solids . The catalysts were characterized through XRD and TPR. TGA  and Raman spectroscopy were used to determine presence and nature of the carbonaceous deposits. None of the catalysts assayed showed carbon deposition through TGA although the Raman spectra always included   bands assigned to graphitic carbon. For the  Pt and Rh catalysts   significant increases in CH4 and CO2 conversions were recorded in a membrane reactor.  Despite their similar activities, the Rh/La2O3 was much more stable than the Pt/La2O3 formulations. The origin of the deactivation was found to be the sintering of the platinum after 100 hours on stream at 823 K. Rh interacted more strongly with the support and this impaired the sintering of the well-dispersed metal.