Enhanced thermal stability of lean methane combustion by structural interactions of CeO2 with Pt/3DOM LaFeO3 catalysts

A new high efficiency catalyst for low concentration methane combustion is reported in this paper. In this catalyst, Pt and CeO2 nanoparticles are dispersed on the wall surface of LaFeO3, which greatly improve its catalytic activity, oxygen mobility and thermal stability. [Display omitted] •Pt/CeO2/3DOMLaFeO3 shows excellent catalytic activity and thermal stability for methane combustion.•The excellent methane catalytic activity is due to the relatively uniform surface loading of Pt nanoparticles on 3DOM LaFeO3.•The presence of CeO2 nanoparticles on the surface of 3DOM LaFeO3 induced the formation of more oxygen vacancies, there by improving the material's reducibility and oxygen mobility.•The interaction between CeO2 and Pt enhanced the catalytic activity and thermal stability of the catalyst.•The effect of CeO2 becomes more obvious with the increase of roasting temperature. It is challenging to load precious metals nanoparticles on LaFeO3 perovskite with small specific surface, and to improve the thermal stability of precious metals is also very difficult. Therefore, it is of great significance to disperse precious uniformly on perovskite with low specific surface area and to make the catalyst with high catalytic activity and thermal stability. In this work, we develop series of perovskite-based methane combustion catalysts with good catalytic activity and stability. Compare with traditional LaFeO3 catalysts, the catalytic activity of three-dimensional ordered macroporous (3DOM) LaFeO3 significantly improves by loading Pt. In addition, its thermal stability is significantly improved by adding CeO2, especially at high roasting temperature (800 °C). The 1 wt%Pt/10 %CeO2/3DOM LaFeO3 catalysts shows the highest catalytic activity in which the T10, T50 and T90 are 362 °C, 433 °C and 502 °C, and its recaction temperature of T50 is decreased by 50 °C compare with Pt/3DOM LaFeO3 (800). The different physical and chemical characterizations suggest that the coupling of Ce3+ and Fe2+ induces the formation of a large number of oxygen vacancies, which promotes the oxygen mobility and th oxygen storage capacity during the methane oxidation process. More importantly, the CeO2 addition contributes to the Pt-CeO2 interaction with Ce-O-Pt bond formation, which greatly improves the thermal stability of the catalyst, and this Pt-CeO2 interaction strength becomes more obvious with the increase of calcination temperature. Furthermore, the in-situ DRIFT experiments indicate th