HDO of Methyl Palmitate over Silica-Supported Ni Phosphides: Insight into Ni/P Effect

Irina Deliy, Ivan Shamanaev, Evgeny Gerasimov, Vera Pakharukova, Ilya Yakovlev, Olga Lapina, Pavel Aleksandrov, Galina Bukhtiyarova
2017 Catalysts  
Two sets of silica-supported nickel phosphide catalysts with a nickel content of about 2.5 and 10 wt % and Ni/P molar ratio 2/1, 1/1 and 1/2 in each set, were prepared by way of a temperature-programmed reduction method using (Ni(CH 3 COO) 2 ) and ((NH 4 ) 2 HPO 4 ) as a precursor. The Ni x P y /SiO 2 catalysts were characterized using chemical analysis N 2 physisorption, XRD, TEM, 31 P MAS NMR. Methyl palmitate hydrodeoxygenation (HDO) was performed in a trickle-bed reactor at 3 MPa and 290 •
more » ... at 3 MPa and 290 • C with LHSV ranging from 0.3 to 16 h −1 . The Ni/P ratio was found to affect the nickel phosphide phase composition, PO x groups content and catalytic properties in methyl palmitate HDO with the TOF increased along with a decline of Ni/P ratio and a growth of PO x groups' content. Taking into account the possible routes of methyl palmitate conversion (metal-catalyzed hydrogenolysis or acid-catalyzed hydrolysis), we proposed that the enhancement of acid PO x groups' content with the Ni/P ratio decrease provides an enhancement of the rate of methyl palmitate conversion through the acceleration of acid-catalyzed hydrolysis.
doi:10.3390/catal7100298 fatcat:kymvszjuqvgdzoxoej6w4fn5ly