Preparation and characterization of NiW-nHA composite catalyst for hydrocracking

The synthesis, characterization and catalytic capability of the NiW-nano-hydroxyapatite (NiW-nHA) composite were investigated in this paper. The NiW-nHA catalyst was prepared by a co-precipitation method. Then Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD) and energy dispersive spectroscopy (EDX) were used to analyze this material. In addition, the catalytic capacity of the NiW-nHA composite was also examined by FT-IR and gas chromatography (GC). The results of FT-IR analysis indicated that Ni, W and nHA combined closely. TEM observation revealed that this catalyst was needle shaped and the crystal retained a nanometer size. XRD data also suggested that a new phase of CaWO₄ appeared and the lattice parameters of nHA changed in this system. nHA was the carrier of metals. The rates of Ni/W-loading were 73.24% and 65.99% according to the EDX data, respectively. Furthermore, the conversion of 91.88% Jatropha oil was achieved at 360 °C and 3 MPa h^-1 over NiW-nHA catalyst. The straight chain alkanes ranging from C₁₅ to C₁₈ were the main components in the production. The yield of C₁₅-C₁₈ alkanes was up to 83.56 wt%. The reaction pathway involved hydrocracking of the CC bonds of these triglycerides from Jatropha oil. This paper developed a novel non-sulfided catalyst to obtain a "green biofuel" from vegetable oil.