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La-deficient La1-xCexMnO3 mixed oxides, obtained by selective dissolution in 1 ​M nitric acid, were employed in methane complete oxidation. The majority of the La cations in these perovskites were removed, resulting in increased specific surface areas, better reducibility and greater activity. Incorporation of a small amount of Ce stabilized the structure and a perovskite phase persisted in La-deficient La1-xCexMnO3 mixed oxides after 12 ​h of acid dissolution. La0.95Ce0.05MnO3 after the acid treatment exhibited satisfactory catalytic activity, with T50 and T90 values of 365 and 459 ​°C, respectively, which was even comparable to that previously reported 1% Pd/Al2O3 catalysts. And it showed excellent long-term activity even in the presence of CO2 and H2O.

We develop a host–guest strategy to construct cobalt-doped MnO2 nanofibers with dual reactive sites, which exhibit high activity for propane deep oxidation. After the incorporation of cobalt (the actual molar ratio of Co/Mn up to 0.15), no distinct changes of crystal structure and morphology of MnO2 nanofibers were observed, as evidenced by X-ray diffraction and transmission electron microscopy. The optimized MnCo0.2 nanofibers possessed the advantages of Mn and Co and exhibited the propane conversion of 50% (T50) and 90% (T90) at 205 and 223 °C, respectively. The Co-related species is more responsible for reducing the light-off temperature (T50), whereas the Mn-related species helps more to decrease complete oxidation temperature (T90). Furthermore, the in situ diffuse reflectance infrared Fourier transform spectroscopy results revealed the roles of Co-related species and Mn-related species during propane adsorption and oxidation. The finding demonstrates the win-win effect of two active oxides and provi...