High iso-alkanes production from palmitic acid over bi-functional Ni/H-ZSM-22 catalysts

•Ni/H-ZSM-22 showed excellent catalytic performance in upgrading of palmitic acid.•Higher temperature promoted isomerization while lower favored hydrodeoxygenation.•Melt infiltration was proven to be more effective to prepare bi-functional catalyst.

Bi-functional Ni/H-ZSM-22 catalysts with melt infiltration, incipient wetness impregnation and wet impregnation methods, were used to catalyze palmitic acid. Compared to parent zeolite, there were decrease of relative crystallinity, some blockage effects of micro pores and less strong acid sites after Ni loading. The complete conversion of palmitic acid and 100% alkanes selectivity were achieved at lower temperature (200 °C). No deactivation was observed in five recycle reaction, indicating the excellent catalytic performance and stability of Ni/H-ZSM-22 catalysts. Higher reaction temperature (240-260 °C), more iso-alkanes/n-alkanes formed, while less C16/C15 produced. Additionally, the catalysts prepared by melt infiltration were more inclined to HDO routes and produced more iso-alkanes (0.8 mol ratio of iso-alkanes/n-alkanes) than their counterparts prepared by conventional impregnation methods.

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