Transesterification of vegetable oils by AlPO_xN_y heterogeneous catalysts

Abstract : AlPOxNy are the most studied materials among nitrided phosphates in heterogeneous catalysis. Such catalysts were tested in this work for the transesterification reaction of canola oil. High specific surface areas AlPO4 precursors have been prepared using hydrogel or citrate routes. Nitrided powders obtained after thermal reaction under ammonia flow keep high surface areas and nitrogen contents can be modulated depending on the experimental conditions. Both precursor and oxynitrides have been characterized by BET, oxygen and nitrogen analyses, infrared and NMR spectroscopies. The influence of the metal, the alcohol and the nitrogen content on the catalytic performances was also studied. AlPO4 and corresponding nitrided phases (with N wt.% <10) produce higher catalytic activities for the transesterification of vegetable oils compared to that of the reference catalyst ZnAl2O4.