Three-dimensionally ordered macroporous Eu0.6Sr0.4FeO3 supported cobalt oxides: Highly active nanocatalysts for the combustion of toluene

Three-dimensionally ordered macroporous (3DOM) Eu0.6Sr0.4FeO3-supported cobalt oxide nanocatalysts (yCoOx/3DOM-ESFO; y wt% = 1, 3, 6, and 10) were prepared using the incipient wetness impregnation method. Physicochemical properties of the composite materials were characterized by means of numerous techniques, and their catalytic performance was evaluated for the combustion of toluene. It is shown that all of the samples displayed a well-defined 3DOM architecture with a surface area of 22–31 m2 g−1 and the loaded cobalt oxide nanoparticles with a diameter of 7–11 nm were well dispersed on the surface of the 3DOM-ESFO support. Among the yCoOx/3DOM-ESFO samples, the 3CoOx/3DOM-ESFO and 6CoOx/3DOM-ESFO ones possessed the highest oxygen adspecies concentration and the best reducibility at low temperature, and hence showing the best catalytic performance (the temperatures required for 50 and 90% toluene conversions were ca. 250 and 270 °C at a space velocity of 20,000 mL g–1 h–1, respectively) for toluene combustion. The apparent activation energies (ca. 72 kJ mol−1) of 3CoOx/3DOM-ESFO and 6CoOx/3DOM-ESFO were lower than that (81 kJ mol−1) of 3DOM-ESFO. It is concluded that the enhanced catalytic performance of 3CoOx/3DOM-ESFO and 6CoOx/3DOM-ESFO for toluene combustion was mainly related to their higher oxygen adspecies concentrations, stronger reducibility at low temperature, and better dispersion of cobalt oxide nanoparticles.

yCoOx/3DOM-ESFO (y wt% = 1, 3, 6, and 10) are prepared using the incipient wetness impregnation method. It is found that high oxygen adspecies concentrations, strong low-temperature reducibility, and good dispersion of cobalt oxide nanoparticles are responsible for the good catalytic performance of 3–6CoOx/3DOM-ESFO.Figure optionsDownload as PowerPoint slideHighlights
► yCoOx/3DOM-ESFO catalysts are prepared using incipient wetness impregnation method.
► Cobalt oxide nanoparticles are highly dispersed on the surface of 3DOM-ESFO.
► 3–6CoOx/3DOM-ESFO exhibits high Oads concentration and good reducibility.
► 3–6CoOx/3DOM-ESFO performs well in the combustion of toluene.
► Activity is governed by Oads concentration, reducibility, and CoOx dispersion.