Three-dimensionally ordered macroporous La0.6Sr0.4FeO3−δ: High-efficiency catalysts for the oxidative removal of toluene

Three-dimensionally (3D) ordered macroporous (3DOM) La0.6Sr0.4FeO3-δ (LSF-F127, LSF–PEG, LSF–PEG–EtOH, and LSF–Lysine) with mesoporous or nanovoid-like skeletons were prepared using the surfactant (Pluronic F127, poly(ethylene glycol) (PEG) or l–lysine)-assisted polymethyl methacrylate (PMMA)-templating method in aqueous or 40% ethanol aqueous solution. It is shown that the LSF samples displayed a 3DOM architecture and were of a single-phase orthorhombic crystal structure. The nature of surfactant and solvent could influence the pore structure and surface area of the final product. Treating the LSF precursor first in N2 at 500 °C and then in air at 750 °C favored the formation of 3DOM-structured La0.6Sr0.4FeO3−δ. The porous LSF catalysts performed well in toluene combustion, with LSF–PEG showing the best catalytic performance (T10% = 54 °C, T50% = 225 °C and T90% = 280 °C at 20,000 mL/(g h)). It is concluded that the excellent catalytic performance of 3DOM-structured LSF is associated with their larger surface areas, higher oxygen adspecies concentrations, better low-temperature reducibility, and high-quality 3DOM structures.

3DOM-structured La0.6Sr0.4FeO3−δ (LSF-F127, LSF–PEG, LSF–PEG–EtOH, and LSF–Lysine) were prepared using the surfactant (F127, PEG or l–lysine)-assisted PMMA-templating method in aqueous or 40% ethanol aqueous solution. The excellent catalytic performance of 3DOM LSF for toluene combustion is related to the large surface area, high oxygen adspecies concentration, and good low-temperature reducibility as well as the high-quality 3DOM structure.Figure optionsDownload as PowerPoint slideHighlights
► 3DOM La0.6Sr0.4FeO3−δ are prepared by the surfactant-aided PMMA-templating method.
► Surfactant addition favors the formation of mesoporous or nanovoid-like skeletons.
► 3DOM La0.6Sr0.4FeO3−δ are high in Oads content and good in low-temp. reducibility.
► 3DOM La0.6Sr0.4FeO3−δ catalysts perform well in the combustion of toluene.
► Surface area, Oads content, and reducibility account for the good catalytic activity.