Synthesis of Ni Catalyst Supported on SiO₂-ZrO₂ Binary Oxide for Hydrodeoxygenation of Phenol

Hydrodeoxygenation is a one-step reaction that involve the hydrogenation of unsaturated carbon followed with the deoxygenation of the carbon-oxygen bond. This reaction is effective for converting biomass-derived chemicals from bio-oils, fats, woods, and lignocellulosic materials into biofuels using metal-based oxide catalysts. A Ni based-metal oxide catalyst is reported for hydrodeoxygenation reaction of phenol. The catalyst was prepared by a wet-impregnation method using Ni(NO₃)₂.6H₂O dissolved in deionized water and mixed with the previously prepared SiO₂-ZrO₂ binary oxide as support. After calcination and reduction at 500 °C, Ni/SiO₂-ZrO₂ catalyst was obtained. The XRD results showed 2θ peaks for metallic Ni at 30°, 44° and 76°. Additional peaks were detected at 2θ = 35°, 50°, 51°, and 60° for ZrO₂ tetragonal phase. However, peaks were not detected for SiO₂ suggesting amorphous SiO₂-ZrO₂ composite formation. The XRF analysis of Ni loading was detected at 16.45%. The catalyst activity test for hydrodeoxygenation of phenol was performed using a batch reactor at 200 °C for 2 h and 8 h. The GC-MS analysis gave product conversion for 2 h at 16.84% with the selectivity formation of cyclohexanol and cyclohexanone at 48.10% and 45.78% yield, respectively. After a prolonged reaction time of 8 h, 100% selectivity for cyclohexanol was achieved. Product distribution showed that the catalyst is active for hydrogenation of benzene better than-OH or C=O deoxygenation. The results suggest Ni/SiO₂-ZrO₂ could be a potential catalyst for biofuel production via hydrogenation reaction.