MESOPOROUS Ni/NiO-SiO_2 FOR EFFECTIVE HYDRODEOXYGENATION OF STEARIN INTO DIESEL RANGE HYDROCARBONS

摘要

Mesoporous nickel stabilized with silica species as a hydrogenation catalyst to convert a glyceride model compound (stearin) to diesel fuel is studied. The catalyst was synthesized by the hydrothermal method using organosilane template as a source of isolated Si to stabilize the Ni structure as well as to create mesopores. The catalyst was characterized by nitrogen sorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), H_2 chemisorption, X-ray photoelectron spectroscopy (XPS), ammonia temperature-programed desorption (NH_3-TPD), and temperature-programmed reduction (TPR). The material has a high surface area (205 m~2/g), average crystallite size (5.4 nm) by XRD, Ni particle size (7 nm) by H_2 chemisorption, and 20% metal dispersion. The acidity of the catalyst was measured to be 0.28 mmol/g. Catalyst life and activity was measured in a fixed bed reactor. Nearly complete glyceride conversion (100%) and 88% (C10-C17) selectivity have been achieved at 350℃. The conversion and yield of diesel increased with an increase in temperature from 325 to 350℃.