Catalytic methane combustion at low temperatures over YSZ-supported metal oxides: Evidence for lattice oxygen participation via the use of C18O2

• Published in: Catalysis communications 2023-07, Vol.180, p.106704, Article 106704
• Main Authors: Nau, Alexandre, Pointecouteau, Rémy, Richard, Mélissandre, Belin, Thomas, Can, Fabien, Comminges, Clément, Bion, Nicolas
• Format: Article
• Language: English
• Subjects: Carbon dioxide; Catalysis; Chemical Sciences; Engineering Sciences; Isotopic exchange; Lattice oxygen; Methane combustion; Reactive fluid environment; Yttria-stabilized zirconia
• ISSN: 1566-7367; 1873-3905
• DOI: 10.1016/j.catcom.2023.106704

Catalytic methane combustion was carried out over YSZ, Pd/YSZ and Rh/YSZ between 200 and 700 °C. Despite similar light-off curves for Pd/YSZ and Rh/YSZ between 200 and 450 °C, isotopic exchange experiments using CD4 and 18O2 revealed different behaviour of both supported catalysts regarding the activation of reactant molecules. The use of C18O2 isotopic gas was shown to be more appropriate than 18O2 to evaluate the bulk oxygen mobility in YSZ at low temperatures. The exchange of gaseous CO2 with lattice YSZ oxygen atoms, which occurs via surface hydrogen carbonate intermediate species, allowed to demonstrate the contribution of bulk oxygen atoms of YSZ in Rh/YSZ at low temperatures. [Display omitted] •YSZ is a more suitable support than Al2O3 for methane combustion on Rh-based catalysts.•CH bond is more efficiently activated on Pd/YSZ than on Rh/YSZ.•Lattice oxygen in Rh/YSZ catalyst are involved in the combustion of CH4.•Bulk oxygen diffusion is very fast in YSZ at 200 °C.