Study On The Synthesis And Catalytic Performance Of Hydrotalcite-like Compounds Containing Cu, Fe

In this paper, by using simulation including Cu2+and Fe2+wastewater, the instantsynthesis was prepared copper magnesium aluminum and iron magnesium aluminumthree yuan hydrotalcite（HTLCs）. Preparation conditions of two HTLCs and catalyticperformance of oxidative degradation of methylene blue were studied. Catalytic effectswere contrasted and a preliminary analysis of catalytic mechanism.First of all, by using simulation including Cu2+and Fe2+wastewater, the instantsynthesis was prepared CuMgAl and FeMgAl HTLCs. Using single factor experimentinvestigation on the effect of reaction pH value, M2+/M3+mole ratio and M12+/M22+molar ratio on the influence of synthesis HTLCs. Through the experiments to determinethe best CuMgAl HTLCs preparation conditions for: pH=9,(Mg2++Cu2+)/Al3+moleratio=3, Cu2+/Mg2+molar ratio=2. And the best FeMgAl HTLCs preparation conditionsfor: pH=10,(Mg2++Fe2+)/Al3+mole ratio=3, Fe2+/Mg2+molar ratio=1. Using XRD, IR,SEM analysis means for the best preparation conditions of the HTLCs crystal structureand the chemical composition of properties were characterized, and the results proveCu2+and Fe2+into hydrotalcite layer plate, and generate layered structure integrity, andcrystal phase of a single, has a high degree of crystallinity of HTLCs.Secondly, in the best condition of the preparation of CuMgAl and FeMgAl HTLCsto oxidative degradation of methylene blue solution catalytic performance were studiedrespectively.Using single factor experiment investigation on the effect of catalytic time,the catalyst dosing quantity, pH value, the initial concentration of methylene blue and theoxidant concentration on the influence of methylene blue decolorization rate. Throughthe orthogonal experiment to determine the best CuMgAl HTLCs catalytic conditions for:the catalyst dosing quantity=0.75g/L, catalytic time=3h, H2O2concentration=1.5%, pH=7, the methylene blue decolorization rate could reach96.75%when the initialconcentration of methylene blue is20mg/L. The best FeMgAl HTLCs catalyticconditions for: the catalyst dosing quantity=0.75g/L, catalytic time=2h, H2O2concentration=0.5%, pH=2, the methylene blue decolorization rate could reach97.68%when the initial concentration of methylene blue is20mg/L.Finally, the catalytic effects of different HTLCs oxidative degradation of methyleneblue were contrasted and a preliminary analysis of catalytic mechanism. The experiment results show that CuMgAl and FeMgAl HTLCs oxidative degradation of methylene bluehave good catalytic performance. As catalysts, CuMgAl HTLCs has a wider range ofapplicable pH value than FeMgAl HTLCs. On the one hand, In the same initialconcentration of methylene blue, FeMgAl HTLCs is better than CuMgAl HTLCs withdifferent catalyst amount, catalytic time and H2O2Concentration. On the other hand, inthe higher initial concentration of methylene blue, CuMgAl HTLCs catalytic oxidativedegradation of methylene blue decolorization rate is higher than FeMgAl HTLCs. Themain catalytic mechanism is the reaction between Cu2+, Fe2+and H2O2gave hydroxylradical(HO·). Hydroxyl radical breaks organic molecules in methylene blue dye, anddegrade into small molecules.Experiments show instant synthesis method is a hydrotalcite reliable preparationmethod. It can use the water metal ion Cu2+、Fe2+preparation hydrotalcite while deal withwaste water. The production of the method low cost and its process operation is simple.Synthetic hydrotalcite including Cu2+、Fe2+can be used as catalysts, and catalyticoxidation of dye wastewater. Hydrotalcite is a kind of waste utilization efficientenvironmental protection catalyst.