Tailoring metal-support interaction for preferential methanol oxidation over Ag/Ce0.90In0.10Oδ nanocatalysts with different morphology

The deep oxidation of methanol at relative low temperature is of importance for the exhaust purification of methanol-fueled vehicle. Adjusting the metal-support interaction of catalysts is a promising approach to make the combustion of methanol efficiently. The exposed crystal facets of support strongly affect metal-support interaction as well as catalytic performance. Herein, three types of Ce 0.90 In 0.10 O δ nanomaterial with different morphologies (nanorods, nanoparticles , and nanocubes) and uniform Ag nanoparticles were synthesized, and then they were assembled to form Ag/Ce 0.90 In 0.10 O δ catalysts. The Ag/Ce 0.90 In 0.10 O δ -NR showed the best catalytic performance with a T 90 of 149 °C. To explore the mechanism behind the distinct catalytic performance, the supports and catalysts were characterized by XRD, Raman, H 2 -TPR, and XPS. The characterization results confirmed that Ag/Ce 0.90 In 0.10 O δ -NR exhibited higher oxygen vacancy concentration and more reactive Ag 0 species, which were attributed to that Ce 0.90 In 0.10 O δ -NR mainly exposed (110) crystal faces. Specifically, (110) crystal faces possess of the lowest oxygen vacancy formation energy and boost the charge transfer between Ag nanoparticles and support, which converts the Ag + into reactive species Ag 0 . Finally, the cyclicity and stability of the catalysts were tested. After four cycles and 50 h of continuous testing, the catalytic activity of Ag/Ce 0.90 In 0.10 O δ -NR remained basically unchanged, indicating good stability of the catalyst.