Composite catalysts HZSM-5/alumina (CZA) and Al-MCM-41/alumina (CMA) were synthesized and tested for their catalytic cracking activity in the production of biofuel from palm oil. Both composite catalysts were characterized for their structure, acidity and surface morphology. The addition of alumina in the composite catalysts improved their hydrothermal stability due to the changes in the surface morphology. The deactivation of the catalysts was studied by obtaining time on stream data by varying the palm oil to catalyst ratio of 8-16. The deactivation data were analyzed using different activity models and the deactivation parameters were determined. (C) 2009 Elsevier B.V. All rights reserved.