Carbon xerogels prepared at different pH and ceria-carbon xerogel materials with different compositions and synthesized by different procedures were evaluated as catalysts in the ozonation of oxalic acid and the textile dye CI Reactive Blue 5. The prepared samples were characterized by N-2 adsorption at - 196 degrees C. X-ray diffraction and scanning electronic microscopy. All the catalysts containing both cerium oxide and carbon xerogel removed all oxalic acid in solution after 1 h of reaction. Cerium oxide supported on carbon xerogel and carbon xerogel containing 1% of cerium oxide prepared by one-pot synthesis were the most active catalysts for the ozonation of the dye solution. Considering the catalytic activity and the steps involved in the preparation of materials, the carbon xerogel containing 1% of cerium oxide prepared by one-pot synthesis is the most promising catalyst. (c) 2012 Elsevier B.V. All rights reserved.