Deoxygenation of methyl palmitate over SiO2-supported nickel phosphide catalysts: effects of pressure and kinetic investigation

Abstract

In this paper, a series of Ni₂P/SiO₂ catalysts was synthesized using the thermal decomposition of hypophosphite precursors. The resulting catalysts were characterized using XRD, TEM, CO pulse adsorption, atomic adsorption spectroscopy and NH₃-TPD, and the catalytic properties were investigated for deoxygenation of methyl palmitate at different pressures in a fixed-bed reactor. The results indicate that the catalysts at 1.0 MPa and 3.0 MPa have similar activity, and lower pressure is in favour of direct deoxygenation of methyl palmitate. Pseudo first order kinetics were employed to describe the reaction to understand the effect of pressure and temperature and active energy at different reaction pressures was calculated. According to the active energy, the scission of the C–O bond is more difficult than the C–C, and the HDO route was favored at higher reaction pressure and temperature.