TEOS-modified Ni/ZSM-5 nanosheet catalysts for hydroconversion of oleic acid to high-performance aviation fuel: Effect of acid spatial distribution.

Ni/ZSM-5 nanosheet catalysts with different Si/Al ratios were modified by chemical liquid deposition (CLD) of tetraethoxysilane (TEOS) to tailor their acid spatial distribution. Their catalytic performance was evaluated with the hydroconversion of oleic acid to aviation-fuel-range-alkanes (AFRAs) at different reaction temperatures and H 2 pressures. The modified catalysts inherit the nanosheet structure with decreased external Brønsted acid concentration, especially the strong one. External Brønsted acid sites mainly favor the cracking of the deoxygenated products (C 17 /C 18). Internal Brønsted acid sites mainly enhance the isomerization of the linear AFRAs. And the catalytic activity of the external Brønsted acid sites was more sensitive to reaction temperature than that of the internal ones. The deoxygenation and cracking reactions were also more sensitive to H 2 pressure compared to the isomerization reaction. High AFRA selectivity of 51.4% as well as high iso/n -alkanes ratio of 1.7 were achieved at 250 °C and 10 bar over NS200(1). Image 1 • CLD tailors external acid sites with similar pore structures and Ni distributions. • External B acid sites mainly favor the cracking of the deoxygenated products. • Internal B acid sites mainly enhance the isomerization of the linear AFRAs. • Cracking reaction is more sensitive to temperature and pressure than isomerization. • A high AFRA selectivity of 51.4% with high iso/n -alkanes ratio of 1.7 is achieved. [ABSTRACT FROM AUTHOR]