A method aiming to prepare more uniform Cu-Zn co-precipitate by coupling of diffusion and reaction process was probed in this article and Cu/ZnO co-precipitated catalysts with high catalytic activity were prepared by introducing water layer into the microreactor and adjusting the ratio of water layer to the total flow. The microstructures and evolution process of the catalysts were analyzed by HRTEM/EDS

X-ray diffraction (XRD)

thermogravimetric analysis (TG)

hydrogen temperature-programmed reduction (H2-TPR)

and N2O chemical reaction methods. The results show that the proportion of water layer increases

the Cu-Zn distribution of the initial precipitate is more uniform

and zinc content in the precursor obtained by the aging is increased

the contact area of the oxide CuO and ZnO is increased

and the interaction force is continuously enhanced. Therefore

larger contact area between calcined oxides CuO and ZnO was achieved leading to better dispersibility and stronger interaction with the final catalytic activity of the catalyst significantly enhanced. Numerical analysis based on the model established by MATLAB revealed that the uniformity caused by slower reaction rate of Zn2+ can be inhabited by faster diffusion rate of its own. The diffusion-reaction equilibrium region

defined as capable to obtain uniform precipitate

was enlarged with the increasing ratio of water layer and larger proportion of uniform precipitate was achieved simultaneously.