Catalytic oxidation of phenol with H₂O₂ over VO_x/GaSiAlO_x catalyst

The GaSiAlO_x composite oxide and the VO_x/GaSiAlO_x series catalysts have been prepared through the hydrothermal synthesis method. Meanwhile, the physicochemical properties of the catalysts were characterized by means of XRD, SEM, TEM, XPS and FT-IR, and tested in the hydroxylation reaction of phenol. The morphology of the synthesized gallium-doped GaSiAlO_x composite oxide was 3D cross-linked and coral-like from the SEM characterization. Meanwhile, the XPS characterization results indicate that when Ga was added, the valence state of the active center of the catalyst could be precisely regulated. Based on the precise regulation of the vanadium valence state by Ga₂O₃, the VO_x/GaSiAlO_x catalysts exhibited highly efficient catalytic activity. Under the optimal reaction conditions, the conversion rate of phenol was 71.4% and the selectivity for dihydroxybenzene was 92.3%.