Hydrotreatment of lipid model for diesel-like alkane using nitrogen-doped mesoporous carbon-supported molybdenum carbide

Abstract

The in situ polymerization of aniline as a nitrogen source was adopted to prepare nitrogen-doped mesoporous carbon (NMC), which further supported the molybdenum carbide catalyst for the hydrotreatment of fatty acids. The nitrogen doping drastically enhanced the catalytic performance of Mo2C/N1.0MC-700 with 92.7% conversion and 86.7% selectivity, which are much higher than the values of Mo2C/MC (84.8% and 70.1%, respectively). The kinetic study revealed that the apparent activation energy was reduced greatly after nitrogen doping. In addition, the nitrogen-doped catalyst showed decent stability, and the conversion and selectivity over Mo2C/N1.0MC-700 decreased by 4.4% and 6.9% respectively, after recycling three times. The deactivation mainly resulted from the coke deposition on the surface of catalyst. The high catalytic activity and stability were ascribed to the formation of pyridinic N and pyrrolic N in NMC, which resulted in the high dispersion of Mo, a decrease in the particle size as well as strong interactions between support and active sites. The hydrotreatment conditions of oleic acid were studied, and the optimal reaction conditions were as follows: reaction temperature, 350 °C; initial H2 pressure, 3.0 MPa; n-hexane as solvent. Moreover, the results indicated that a substrate with a saturated carbon double bond and ester group was more easily converted into hydrocarbons.