Preparation of three-dimensionally ordered macroporous La0.6Sr0.4Fe0.8Bi0.2O3−δ and their excellent catalytic performance for the combustion of toluene

Three-dimensionally ordered macroporous (3DOM) La0.6Sr0.4Fe0.8Bi0.2O3−δ (LSFB) were prepared using the surfactant (Pluronic F127, poly(ethylene glycol), l-lysine or xylitol)-assisted polymethyl methacrylate-templating method. Physicochemical properties of the materials were characterized by means of a number of analytical techniques, and their catalytic activities were evaluated for the combustion of toluene. It is shown that the LSFB samples were of 3DOM-architectured single-phase orthorhombic crystal structure. The nature of surfactant and solvent could influence the pore structures and surface areas of the LSFB samples. The Fe4+/Fe3+ or Oads/Olatt molar ratio and low-temperature reducibility correlated with the catalytic performance of the LSFB sample. The porous LSFB samples much outperformed the bulk counterpart, with the LSFB sample derived with xylitol showing the best catalytic activity (the temperatures required for 50 and 90% toluene conversions were 220 and 242 °C at 20,000 mL/(g h), respectively). Apparent activation energies of the porous LSFB samples were in the range of 46–74 kJ/mol. It is concluded that the high oxygen adspecies concentration and good low-temperature reducibility were responsible for the excellent catalytic activity of the porous LSFB sample derived with xylitol.

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► 3DOM La0.6Sr0.4Fe0.8Bi0.2O3−δ are prepared by the surfactant-assisted PMMA-templating method.
► The nature of surfactant and solvent influences the pore structure of La0.6Sr0.4Fe0.8Bi0.2O3−δ.
► Porous La0.6Sr0.4Fe0.8Bi0.2O3−δ outperforms the bulk counterpart for toluene combustion.
► Catalytic activity is governed by the Oads concentration and low-temperature reducibility.