A spherical microsized core-shell catalyst (CuO/ZnO/Al2O3@H-ZSM-5) was synthesized for direct dimethyl ether synthesis from syngas in a micro packed bed reactor. To assist in the preparation and optimization of the core-shell catalyst, a 1D heterogeneous model was developed to simulate diffusion and reactions within the catalyst particles. Using the data obtained from the tubular reactor, kinetic parameters for the catalyst were determined first. Furthermore, simulation showed that thickness and activity of shell have significant effect on the catalytic performance of the core-shell catalyst.