Enhancing the utilization and activity of catalytic materials is crucial in designing catalysts for industrial use. This work achieves these performance enhancements in Rh/Al2O3 catalyzed dry reforming of methane (DRM) at the catalyst pellet level, through engineering catalyst pore network structure. A continuum model, describing the coupled mass, heat transfer and reactions, is developed to optimize the monodisperse and bidisperse catalyst pellets under different temperatures, pressures, and CH4/CO2 ratios. The results show that the preferred pore diameter for the monodisperse catalyst and macropore diameter for the bidisperse catalyst are all 300 nm, above which Knudsen diffusion is not important. Besides, the optimal porosities for the monodisperse and bidisperse catalysts are in the ranges of 0.51–0.59 and 0.61–0.64, which is the result of the trade-off between diffusion and reaction. The optimal bidisperse catalyst can be 56–175% more active but uses 10–18% less catalyst materials when compared to the optimal monodisperse catalyst with the same mesopore size, indicating the great advantage of introducing the optimal macroporosity into mesoporous catalyst pellets for DRM. These results should serve to guide the rational design of industrial catalyst pellets.