Hydrogen Production Using Ni?Rh on La2O3 as Potential Low-Temperature Catalysts for Membrane Reactors

S. IRUSTA, L. M. CORNAGLIA, AND E. A. LOMBARDO

JOURNAL OF CATALYSIS

ACADEMIC PRESS INC ELSEVIER SCIENCE

Lugar: Amsterdam; Año: 2002 vol. 210 p. 7 - 16

0021-9517

The activity and stability of Ni?Rh mono and bimetallic catalysts supported on lanthanum oxide was studied. The catalysts were prepared by wet impregnation with different contents of Rh and 2 wt% Ni. The solids were calcined at 823Kin air flow and were reduced at973Kin flowing hydrogen. The results of the catalytic evaluation in a fixed-bed reactor showed that the Rh solids had the highest activity at 823 K. In order to understand theRheffect, the catalysts were characterized through XRD, XPS, and TPR. No evidence of crystalline Ni phase through XRD was observed in either the calcined or used catalysts. On the other hand, the TPR results suggested a significant metal?support interaction. The XPS data is consistent with this picture. Bimetallic catalysts presented the highest amount of carbon deposits. TGA, DSC, and SEM were used in order to characterize the carbonaceous species. On the catalyst surface at least two types of carbons were detected with different structural properties which did not deactivate the solid. A low carbon deposition was observed on Rh (0.2%)/La2O3 which exhibited a stable activity after 100 h on stream.