CeO2 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 {110} and {100} for rods but {100} for cubes. These nanocrystals have been used in the preparation of a Rh/CeO2 catalyst on an Al2O3 support to test the catalytic activity for ethanol reforming. These catalysts as prepared show good H-2 selectivity compared to catalysts with irregular CeO2 nanoparticles. The {100}/{110}-dominant surface structures play a crucial role in enhancing ethanol reforming; this reaction is important for fuel-cell applications. (c) 2007 Elsevier B.V. All rights reserved.