摘要
The activities of CeO2 nanocubes calcined at different temperatures were tested for catalytic oxidation of o-xylene. Using CeO2 nanocubes as catalysts, complete catalytic oxidation of o-xylene was achieved below 210℃. The CeO2 nanomaterials were characterized by means of BET, X-ray diffraction (XRD), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM). From the TEM images, all CeO2 nanocubes displayed cubic morphology irrespective of calcination temperature. The HRTEM images revealed that these nanocubes were enclosed by reactive {001} planes, which may contribute to the intrinsically catalytic property of o-xylene oxidation. The higher activity of CeO2 nanocubes calcined at 550℃ than those calcined at above 550℃ was attributed to their smaller crystallite size and larger surface area. The influences of reaction conditions were also studied, which found that a higher reaction temperature was necessary for complete catalytic oxidation of o-xylene at higher weight hourly space velocity (WHSV) and o-xylene concentration.
The activities of CeO2 nanocubes calcined at different temperatures were tested for catalytic oxidation of o-xylene. Using CeO2 nanocubes as catalysts, complete catalytic oxidation of o-xylene was achieved below 210℃. The CeO2 nanomaterials were characterized by means of BET, X-ray diffraction (XRD), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM). From the TEM images, all CeO2 nanocubes displayed cubic morphology irrespective of calcination temperature. The HRTEM images revealed that these nanocubes were enclosed by reactive {001} planes, which may contribute to the intrinsically catalytic property of o-xylene oxidation. The higher activity of CeO2 nanocubes calcined at 550℃ than those calcined at above 550℃ was attributed to their smaller crystallite size and larger surface area. The influences of reaction conditions were also studied, which found that a higher reaction temperature was necessary for complete catalytic oxidation of o-xylene at higher weight hourly space velocity (WHSV) and o-xylene concentration.
基金
supported by the National Natural Science Foundation of China (No.50921064,20973193)
the Ministry of Science and Technology of China (No.2007AA061402,2010CB732304)