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 (Ov). Here we report the fabrication of copper-ceria catalysts that contain different copper-ceria structures by adjusting the metal loading content. The Ce0.9Cu0.1O x catalyst shows a H2 production rate as high as 53.2 mLH2 ·gcat -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, Ov is another aspect of catalytic performance. The Ce0.1Cu0.9O x catalyst demonstrates an unexpected rise in the H2 production rate for its abundant Ov. Both the dispersion states of Cu species and the concentration of Ov 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.