Resumen

MUNERA, J.; IRUSTA, S.; CORNAGLIA, L. M.  y  LOMBARDO, E. A.. Production of hydrogen employing Ni-Rh catalysts in membrane reactors. Lat. Am. appl. res. [online]. 2003, vol.33, n.2, pp.73-78. ISSN 0327-0793.

Rh, Ni and Rh-Ni catalysts were prepared by wet impregnation of La₂O₃. The Rh content was modified but the Ni loading was kept constant at 2 wt%. The solids were calcined at 823 K in air flow and were reduced at 973 K in flowing hydrogen. The activity, stability, and residue formation during the CO₂ reforming of CH₄, of all the catalysts were tested in a fixed-bed reactor. Those with low carbon deposition were used in a Pd-Ag membrane reactor. The Rh solids showed the highest activity at 823 K. In order to understand the Rh effect, the catalysts were characterized through XRD and TPR. No evidence of crystalline Ni phase through XRD was observed in either the calcined or used catalysts. On the other hand, both the TPR and XPS results suggest a significant metal-support interaction. The bimetallic solids presented higher carbon deposition. The carbonaceous species formed on stream were characterized through thermal analysis. At least two types of carbons were detected on the catalyst surface with different structural properties which did not affect the catalytic activity. A low carbon deposition was observed on Rh/La₂O₃ which exhibited a stable activity after 100 h on stream. The monometallic Rh solids were tested in the membrane reactor, varying the pressure drop across the Pd-Ag alloy. A significant increase in reactant conversions was obtained when the membrane reactor was used.

Palabras clave : Hydrogen; CO₂ Reforming; Ni-Rh Catalysts; Membrane Reactor.

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