H2-Free Deoxygenation and Cracking of Long-Chain Trimethylolpropane Trioleate with FeNi/TiO2 Bimetallic Catalysts for Biojet Fuel Production

Development of efficient catalysts is important to promote the deoxygenation of oils and fats for the production of biofuels. In this study, several bimetallic catalysts including Fe, Co, and Ni were impregnated onto TiO2 and evaluated for their efficacy in deoxygenating long-chain trimethylolpropane trioleate (TMPTO) under a N2 atmosphere. FeNi/TiO2 exhibited the highest selectivity of 65.7% for C8–C16 hydrocarbons with a relatively good 85.3% deoxygenation performance. The catalyst maintained a stable deoxygenation efficiency of around 70.6% and a selectivity of 46.7% after four runs. Impregnation of transition metals leads to a decrease in the specific surface area, while the additional active sites facilitate deoxygenation and cleavage reactions. The acidic sites provided by Fe and TiO2 supports and the electronic modulation of Ni enhance the ability of the catalyst to crack C–O bonds. The results demonstrate the potential of using transition metals under a N2 environment to convert super long-chain oxygenated fatty acids into jet-fuel-range hydrocarbons.