Synthesis of p-hydroxybenzaldehyde by liquid-phase catalytic oxidation of p-cresol over PVDF modified cobalt pyrophosphate

The influence of the wettability of a catalyst on the performance of the liquid phase oxidation of p-cresol was investigated. It was found that the surface hydrophobicity of a catalyst, which can be changed by modification with various loadings of polyvinylidene fluoride(PVDF), has a promotion effect on the catalytic performance. At the same time, the reaction parameters such as oxygen pressure, molar ratio of NaOH to p-cresol, reaction temperature and time on the catalytic performance in the liquid-phase oxidation of p-cresol were optimized. As a result, 10%(mass fraction) PVDF modified cobalt pyrophosphate gave the highest conversion of 94.2% of p-cresol with a selectivity of 94.4% for p-hydroxybenzaldehyde at 348 K and a molar ratio of 4:1 of NaOH/p-cresol and an oxygen pressure of 1.0 MPa for 3 h.