Preparation And Performance Of A Novel Copper-cobalt Composite Heterogeneous Fenton-like Catalyst

This paper aims to develop a novel heterogeneous Fenton-like catalyst which has a wide pH range and high catalytic efficiency. Contents of this paper is divided into three parts: The first is the optimization of catalyst preparation conditions of novel copper-cobalt composite heterogeneous Fenton-like catalyst. The catalyst was prepared by a modified hydrothermal method and characterized by SEM,TEM, XRD and FT-IR, used the degradation of methyl orange as the parameter, studied the factors(including the activity of the elements cobalt and copper ratio, surfactant, reaction time and temperature) which affect the performance of the catalyst, such as morphology, structure and catalytic degradation, by a single factor experiment;Second is the performance of the catalyst. Used the catalyst and hydrogen peroxide as the simulated contaminants of heterogeneous Fenton-like system for the degradation of methyl orange, explored the initial pH value of the solution, the dosage of the catalyst, the dosage of hydrogen peroxide, the reaction temperature and other factors on the performance of the catalyst. Based on single factor test, optimized the catalyst degradation process parameters through response surface methodology, in addition,the catalyst’s reuse and stability were explored under optimal conditions; Finally,researched the mechanism of the catalytic degradation of methyl orange. The results are as follows:(1) Optimum parameters for preparation of the novel cobalt copper heterogeneous Fenton catalyst was: active elements ratio of Co and Cu was 5:2,surfactant was propionaldehyde, the reaction temperature was 180 ℃, reaction time was 48 h. Under these conditions, the catalyst exhibited irregular hexagonal sheet-like crystalline structure with sizes in the range of 0.50-5.00μm, there were gaps between the catalyst particles. Besides, the main components of the catalyst particles were cobalt oxide and cuprous oxide which has high purity.(2) Through the single factor text, the follows could be found: the novel cobalt-copper complex heterogeneous Fenton-like catalyst has high catalytic performance in the pH range of 2.00-10.00; the optimum dosage of catalyst was 3.00g/L; the degradation rate increases with the increase of hydrogen peroxide, and finally tends to balance; COD degradation rate increases with the increasing of temperature.The optimum process parameters for the degradation methyl orange by response surface method were: initial pH of the solution is controlled at 8.00, the dosage of catalyst was 3.20 g/L, the dosage of hydrogen peroxide was 43.80 mL/L, reaction temperature was 49.94 ℃, reaction time was 40 min, COD degradation rate was92.78% under optimal conditions. In addition, under optimal conditions, the catalyst test was repeated and the results showed that the catalyst still showed some catalytic properties after reused three times, which indicated the catalyst had a certain recycling value.(3) The UV-Vis spectra of methyl orange speculated that decolorization of methyl orange was mainly because the chromophore group azo bond and the benzene ring structures were oxidized to colorless compound or completely oxidized to water and carbon dioxide. Studied the mechanism of the catalytic degradation of methyl orange found that the reason catalyst had high catalytic performance was that the active element cobalt and copper have Fenton-like behavior and high redox potential;Synergy between copper and cobalt ions in the reaction process; the catalyst had a wide pH range was because of the broad precipitation range of copper and cobalt ions.This paper developed a novel cobalt-copper complex heterogeneous Fenton-like catalyst, the study of the performance of the catalyst will provide reference to practical engineering application.