The objective of the study is to illustrate the advantages with using ceria–zirconia instead of promoted alumina as support for rhodium-based catalysts in oxidative steam reforming of biodiesel. The evaluation is based on long-term oxidative steam reforming experiments where the stability and durability of the catalysts are evaluated. The durability and fuel conversion of the two catalysts were comparable. However, the H2 yield of the ceria–zirconia supported catalyst was 10 % higher than for the catalyst supported on promoted alumina after 65 h on stream. Included are also measurements of the acidity of the catalysts, where it was concluded that the promoted alumina catalyst was significantly more acidic. The acidity of the materials could then be related to the amount of coke deposited, where the amount of coke on the alumina catalyst was almost five times higher after 50 h of operation compared to the ceria–zirconia catalyst.