Depolymerization of purified organosolv eucalyptus wood lignin by heterogeneous catalysts, cobalt polyphosphate (CoP₂O₆) and calcium phosphate (β-CaP₂O₆) was investigated. A total syringol yield of 16.7% was achieved with β-CaP₂O₆ in a methanol–water (50/50, w/w) solvent system after depolymerization at 300 °C for 1 h, showing the selectivity of the catalyst.