Efficiency of H₂ Production Influenced by CeO₂ Content-Dependent Copper–Ceria Interaction

The interaction between active sites and the support plays a crucial aspect in the methanol steam reforming (MSR) reaction, which often influences the dispersion states and concentration of surface oxygen vacancies (O_v). Here we report the fabrication of copper-ceria catalysts that contain different copper-ceria structures by adjusting the metal loading content. The Ce_0.9Cu_0.1O _<i>x</i> catalyst shows a H₂ production rate as high as 53.2 mL_H₂ ·g_cat ^-1·min^-1 at 250 °C, benefiting from the highly dispersed Cu species. When the Ce/Cu molar ratio is reduced further, the H₂ production rate continues to decrease due to the agglomeration of Cu. However, O_v is another aspect of catalytic performance. The Ce_0.1Cu_0.9O _<i>x</i> catalyst demonstrates an unexpected rise in the H₂ production rate for its abundant O_v. Both the dispersion states of Cu species and the concentration of O_v are significant. Among them, the optimal Ce/Cu ratio is 1/9 for CO-free MSR, which is potentially beneficial in a clean H₂ production area.