Catalytic performance and deoxygenation path of methyl palmitate on Ni2P/SiO2 synthesized using the thermal decomposition of nickel hypophosphite

Abstract

In this paper, the catalytic performance and deoxygenation path of methyl palmitate on Ni₂P/SiO₂ catalysts were systematically studied in a continuous flow fixed-bed reactor. A series of Ni₂P/SiO₂ catalysts (with different molar ratios of P/Ni and Ni₂P loadings) were synthesized at 300 °C using the thermal decomposition of nickel hypophosphite. The increased molar ratio of P/Ni generates phosphate-rich nickel phosphide catalysts and increasing conversion. Interestingly, Ni₂P/SiO₂ showed significantly higher conversion of methyl palmitate in comparison with Ni/SiO₂. Furthermore, an activation temperature higher than 500 °C would significantly reduce the catalytic activity, as a result of the sintering of Ni₂P. The pressure in a range of 3.0 to 0.5 MPa almost has no effect on the deoxygenation of methyl palmitate, but significantly affects the reaction path and product distribution. Finally, a possible deoxygenation path over Ni₂P/SiO₂ was proposed based on a GC-MS investigation.