Copper-containing mixed metal oxides derived from layered precursors: control of their compositions and catalytic properties

In this article, a series of Cu-containing mixed metal oxides were obtained by calcination of layered double hydroxides (LDHs) precursors with Cu/Zn/Al atomic ratios ranging from 1: 3: 1 to 3: 1: 1 in synthesis mixture at 773 K. The materials were characterized by means of powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR), nitrogen sorption experiments, and X-ray photoelectron spectroscopy (XPS). The results indicate that Cu/Zn/Al cationic ratios in precursors could control the compositions of surface species on the resultant calcined LDHs. Furthermore, The catalytic activities of phenol oxidation in aqueous solutions by hydrogen peroxide over the calcined LDHs as catalysts were also tested. It is found that the high catalytic activity is relative to the high amount and dispersion of composite metal oxides containing active Cu2+ reaction centers on the surface of calcined samples, and the lattice oxygen species on the surface are beneficial to the deep oxidation of phenol.