Studies On Selective Catalytic Oxidation Of Cresol To Hydroxybenzaldehyde

Hydroxybenzaldehyde is an important chemical intermediate in organic synthesis, of which p-hydroxybenzaldehyde and m-hydroxybenzaldehyde are most widely used, they are widely used in medicine, pesticides, spices, electroplating, food, dye, liquid crystal, oil processing, polymer materials, additives and other areas, due to the widely application and the high added value of its production, its products have been in short supply, causing prices have been high. Therefore, it is very necessary to further study and improve their production methods.In this paper, the selective oxidation reaction of cresol to hydroxybenzaldehyde was studied, especially the selective oxidation situation with the effect of the loaded catalyst and the oxygen in the liquid phase.It found that the catalyst of Co2+and Cu2+ surpported on the TiO2 have a great catalytic activity in the selective oxidation reaction.In this paper, the new catalyst was prepared by unexpensive metal cobalt and copper as active component, iron and cerium salt as promoter, and TiO2 as carrier using impregnation method. The performances of these catalysts were characterized using XRD, IR methods and HPLC was used to characterized the test reactions. The catalyst characterization results and the test results of HPLC was used to evaluate the cataylst, in order to select the best preparation conditions of the catalyst, the catalyst preparation conditions on the catalytic activity of the catalyst was analyzed. Results show that the calcined temperature, time and the distribution ratio of the metal ions have great influence on catalytic performance.In this paper,the catalytic oxidation process conditions were also optimized, in the selective oxidation reaction of p-cresol, under the optimum reaction , the conversion rate of p-cresol reaches 100%, the selectivity of p-hydroxybenzaldehyde is 95.2%; in the selective oxidation reaction of m-resol, under the optimum reaction, the conversion rate of m-cresol reaches 55.4%, the selectivity of m-hydroxybenzaldehyde is 37.5%, it shows that this catalyst does not apply to m-cresol catalyzed oxidation.