Deoxygenation of triolein to green diesel in the H2-free condition: Effect of transition metal oxide supported on zeolite Y

H2-free deoxygenation is a very important process in producing high-quality biofuel without the use of H2 gas supply. Considering the costly price of the noble metals, transition metal (TM) based catalysts are more affordable, and the performance is comparable to the noble metal-based catalyst. In this study, TMO supported on zeolite Y catalysts (Ni-, Cu-, Co-, Zn- and Mn-Y) are prepared via wet-impregnation for deoxygenation of triolein, a model compound of non-edible oil under H2-free condition. The deoxygenation activity of TMO supported on zeolite Y is following the order of Ni-Y > Co-Y > Cu-Y > Mn-Y > Zn-Y. The nickel oxide supported on zeolite-Y (Ni-Y) shows the highest conversion up to 76.21 % with 84.28 % hydrocarbon selectivity after reacted at 380 °C for 2 h. Besides, the selectivity toward diesel range hydrocarbon is 92.61 %. The superior deoxygenation activity of Ni-Y can be related to synergistic effect between the reduced B/L and high hydrogenolysis ability of Ni that promote the decarboxylation reaction, suppress the cracking and polymerization of heavy hydrocarbon. Therefore, Ni-Y is a potential catalyst to obtain high quality green diesel from non-edible oil through catalytic deoxygenation without addition of external H2 source.