Facile synthesis of Mo/Al₂O₃–TiO₂ catalysts using spray pyrolysis and their catalytic activity for hydrodeoxygenation

In this study, spherical mixed oxides of Al₂O₃ and TiO₂ supported molybdenum (Mo) catalysts, Mo/Al₂O₃−TiO₂, were successfully prepared using a novel approach combining sol-gel and spray pyrolysis (SP) methods. First, both boehmite sol and titania sol were prepared by a sol-gel process, and then molybdate salt was dispersed in the sol mixture with the assistance of citric acid, followed by spray pyrolysis of the mixed precursor solution. Structural analyses of prepared catalysts showed that the dispersion of active sites was affected by the TiO₂ concentration in the Al₂O₃−TiO₂ mixed oxide support. The catalytic activities of reduced catalysts were investigated for hydrodeoxygenation (HDO) of palmitic acid, which is the main component of microalgae–derived biocrude. The results show that the Mo/Al₂O₃–TiO₂ catalysts exhibited excellent catalytic performance for the HDO of palmitic acid.