Study On The Preparation And The Activity In Phenol Degradation Of Cu Series Wet Oxidation Catalyst

Wet air oxidation (WAO) is one technology for the treatment of hazardous, toxic and high concentrated organic wastewater under the high temperature (125-320 ℃) and pressure (0.5-20MPa). However, the severe operation conditions have restricted it from being widely used. Catalytic wet oxidation technique (CWAO) gains great attention for it could decrease reaction temperature and press, shorten reaction time and raise oxidation efficiency, so the development of catalysts with high activity and stability has been focally researched and become the key point of CWAO application. In this paper, load type catalyst CuO/γ-Al2O3 was prepared by soakage. The technical conditions such as concentration of the soakage solution, soakage time, calcination temperature, calcination time, etc were optimized, and the optimum conditions was determined as follows: concentration of CuSO4 is 6%,soakage temperature is 30℃,soakage time is 6h, calcination temperature is 400℃,calcination time is 4h。Applied this techinics to CWAO of phenol and optimized the processing parameters such as reaction temperature, oxygen partial pressure, intension of stir and dosage of the catalyst. The optimized conditions was get as follows: reaction temperature is 180℃,oxygen partial pressure is 3MPa,intension of stir is 600r/min and dosage of the catalyst is 2g/L。XRD, XPS, SEM were used to investigate the relationship between the surface microstructure and catalytic activity and that between the reusing times and catalytic activity of CuO/γ-Al2O3, The results showed that the decreasing of the catalytic activity should be ascribed to the phase change of the support and the formation of a new complex CuAl2O4 in high temperature. Chosen Ce as the aids, the doping modification of CuO/γ-Al2O3 catalyst was proceeded then CuO-CeO2/γ-Al2O3 catalyst was prepared by soakage. TG-DTA,XRD,XPS,SEM were used to investigate the effects of Ce doping on the surface microstructure of catalyst, it can be conclude that the introducing of Ce effectively restrained the phase change of support, which turned fromγ-Al2O3 to α-Al2O3, and the formation of CuAl2O4, which was produced by the reaction between CuO and support during the reaction of wet oxidation effectively. The effects of the concentration of Ce and reusing times on the catalyst activity were determined by the degradation of the phenol synthetic wastewater. The results showed that catalyst 6%CuO-6%CeO2/γ-Al2O3 exhibited the best catalytic activity. The operation life of the catalyst was investigated at the same time.