Insights into the promotion mechanism of ceria-zirconia solid solution to ethane combustion over Pt-based catalysts

Abstract

Pt/Ce0.5Zr0.5O2 (denoted as Pt/CZ11) and Pt/Al2O3 with identical Pt loading and dispersion were prepared and evaluated for ethane catalytic combustion. Pt/CZ11 exhibited higher activity than Pt/γ-Al2O3 even with similar Pt dispersion. Combined with various characterizations, it was revealed that the enrichments of surface active oxygen and oxygen vacancy on Pt/CZ11 facilitated ethane combustion owing to the strong interaction between Pt and Ce-Zr solid solution. Moreover, in situ DRIFT results demonstrated that different reaction mechanisms were followed over Pt/CZ11 and Pt/Al2O3. The front followed the single-site Langmuir-Hinshelwood (L-H), in which C2H6 and O2 were absorbed and activated on Pt sites. While the coupled reaction mechanism involving L-H and Mars-van Krevelen (MvK) were illustrated over Pt/CZ11, on which ethane can be activated on Pt sites and CZ11 support. More mechanistic insights into ethane combustion provided the guidelines for the developments of catalysts with superior performance for light-carbon alkane volatile organic compounds.