Hydrotreatment of Anisole and Furfural as Model Compounds of Bio-oil over Chromium Modified Nickel-Based Catalysts

Hydrotreatment of anisole and furfural as model compounds of carbohydrates and lignin fraction of pyrolysis liquids was studied using Cr-containing (from 0 to 18 wt%) Ni-based sol-gel catalysts. The catalytic activity of Ni−Cr catalysts was carried out in the autoclave at pressure 6.0 MPa of hydrogen and temperature 320 °C and 100 °C for anisole and furfural hydrotreatment, respectively. Addition of Cr to Ni-SiO₂ catalyst results in increasing activity in anisole conversion with the maximum for NiCr₁₀-SiO₂ catalyst. This is attributed to the formation of dispersed metallic Ni detected by X-ray diffraction method. Moreover, the Cr addition increases the corrosion resistance of samples in the medium of acetic acid at boiling temperature. In furfural conversion, the Cr-doped catalysts showed the lowest activity, however, for NiCr₁₀-SiO₂ catalyst the high selectivity to tetrahydrofurfuryl alcohol formation was observed.