CeO 2 nanocrystals with cube and rod shapes synthesized under hydrothermal conditions have been used to prepare Rh/CeO 2 catalyst (5% mass) on Al 2O 3 support to test their catalytic activity for ethanol reforming. The catalysts as prepared show H 2 selectivity superior to a catalyst with irregular CeO 2 nanoparticles. Although the shape of CeO 2 particles gradually altered and the activity decreased during the reforming, the {1 0 0}/{1 1 0}-dominant surface structures play a crucial role to enhance the ethanol reforming, which is important for fuel-cell applications. CeO 2 nanocrystals of cubic and rod shape have been synthesized under hydrothermal conditions on controlling the pH, temperature and duration of reaction. High-resolution transmission electron microscopy indicates that exposed crystal planes are {1 1 0} and {1 0 0} for rods but {1 0 0} for cubes. These nanocrystals have been used in the preparation of a Rh/CeO 2 catalyst on an Al 2O 3 support to test the catalytic activity for ethanol reforming. These catalysts as prepared show good H 2 selectivity compared to catalysts with irregular CeO 2 nanoparticles. The {1 0 0}/{1 1 0}-dominant surface structures play a crucial role in enhancing ethanol reforming; this reaction is important for fuel-cell applications.