Ethanol reforming over Ni/CeGd catalysts with low Ni content

The catalytic performance of Ni/CeGd SOFC anodes with low Ni content (18%wt) prepared by a hydrothermal method for ethanol conversion reactions was evaluated. Calcination temperature and reaction conditions significantly affected the activity and stability of the samples. Increasing calcination temperature decreased ethanol conversion. This was likely due to the larger CeGd crystallite size. All samples deactivated during reaction under pure ethanol at 773 K. The addition of water or oxygen to the feed and the increase of reaction temperature improved catalyst stability. Scanning electron microscopy and thermogravimetric analysis showed that the deactivation was due to carbon formation. In the presence of oxygen or water, the mechanism of carbon removal was favored. Moreover, carbon formation was not favored at high reaction temperature due to the reverse of the Boudouard reaction as well as the promoting effect of the support on the carbon gasification reaction.

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► Ni/CeGd SOFC anodes with low Ni content (18%wt) prepared by a hydrothermal method.
► Calcination temperature and reaction conditions affected activity and stability.
► Activity reduced at high calcination temperature due to larger CeGd crystallite size.
►  The addition of water or oxygen to the feed inhibits carbon formation at 1073 K.
► This result is due to the promoting effect of the support on carbon gasification.