Title: Synthesis and characterization of hydrotalcites as catalysts for the hydroxylation of phenol
Abstract
Cu/Mg/Al hydrotalcite-like compounds with different Cu/Mg/Al molar ratios (5:1:2;3:1:4/3;1:1:1;1:3:4/3;1:5:2)were synthesized by the co-precipitation method and then they were submitted to the microwave radiation in order to improve the crystallinity and minimize the particle size of the solids. The synthesized compounds were characterized by XRD、IR and SEM. The results showed that the structure of hydrotalcite-like compounds were more integrated with the increasing of the content of Cu. Microwave was used to intercalate anions(WO42+、MoO42+ and VO32+ )into the inner layer, the XRD showed that the intercalations were not succeed ,but from the colour of the intercalated samples ,we suggest that the anions may loaded on the surface of the hydrotalcite-like compounds. From the catalysis test results , hydrotalcite-like compounds loaded with VO32+ have good catalytic activity, but with WO42+and MoO42+,the catalytic activity reduced.