Role of the oxide support on the
performance of Rh catalysts for the autothermal reforming of gasoline and
gasoline surrogates to hydrogen
Magali Ferrandon and Theodore Krause
Argonne National Laboratory, Chemical Engineering Division, Argonne, IL
60430-4837, USA
Abstract
Catalysts consisting of 2 wt% Rh deposited on Gd-CeO2, Y-ZrO2,
γ-Al2O3, La-Al2O3, and CaAl12O19
were tested for the autothermal reforming (ATR) of isobutane and sulfur-free
gasoline. The catalysts were characterized for activity by microreactor tests
and temperature-programmed reduction (TPR), and for physical properties by
surface area measurements, CO chemisorption, X-ray diffraction (XRD), and
extended X-ray absorption fine structure (EXAFS) analyses. The order of activity
for ATR of isobutane was Rh/La-Al2O3 > Rh/Y-ZrO2
> Rh/Gd-CeO2 > Rh/γ-Al2O3 > Rh/CaAl12O19,
which paralleled the ranking of the catalysts based on the dispersion and
reducibility of Rh, with Rh/La-Al2O3 having the highest
dispersion and the lowest reduction temperature. After subjecting the catalysts
to an accelerated ageing process, the activity for ATR of isobutane was similar
for all catalysts except for Rh/Gd-CeO2, which experienced a significant loss in
steam reforming activity. Rhodium dispersion measurements confirmed that the
ageing process had caused Rh to sinter on all of the supports. A major
conclusion from this study is that the primary effect of the support was on the
dispersion of Rh.
Copyright ©2006 Elsevier B.V.
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