Mixed Ni-Mn-oxide systems as catalysts for complete oxidation: Part II. Kinetic study of liquid-phase oxidation of phenol Original Research Article

The catalytic activity of a new mixed Ni-Mn-oxide system has been studied in liquid-phase oxidation of phenol. The efficiency of the process has been evaluated based on the degree of conversion, α (%) and the rate constant, k (min−1). With heterogeneous oxidation of PhOH, carried out under mild conditions (T=35 °C, pH=7.0, mcat.=2 g dm−3) the complete oxidation is achieved to the 30th minute. The following intermediates (their presence being proved using UV spectrometry and HPLC) are obtained in the course of oxidation process: catechol, benzoquinone, hydroquinone, and hydroxyhydroquinone. The intermediates are further oxidized to CO2 (proved by GC and chemical analyses) and carboxylic acids.