The effect of Cu–Zn distribution in zincian malachite on the formation of individual CuO and ZnO particles

Cu–Zn distribution in zincian malachite was regulated in preparation process, and its effect on the formation of CuO and ZnO during the thermal decomposition was investigated. In the HRTEM images, there are obvious individual particles comprised of pure CuO or ZnO in the calcined samples prepared by conventional batch reactor (BR), whereas no pure particle appears in the samples prepared by microchannel reactor (MR). The fraction of Zn 2+ incorporating into malachite and the relevance between Cu and Zn confirmed MR precursors were more homogeneous than BR precursors. The TGA/DTG curves showed the uniform distribution caused more interfaces and stronger interaction between Cu and Zn, which could depress the formation of individual CuO and ZnO particles. The combined effects of non-uniform distribution and thermodynamics de-mixing lead to the appearance of CuO and ZnO particles. The result illustrates how the Cu–Zn distribution acts on the thermal decomposition and affects catalyst structure.