The Catalytic Combustion of Methane over Fe/CexZr0.9-xLa0.1O1.95-Al2O3 Monolith Catalyst

A series of CexZr0.9-xLa0.1O1.95-Al2O3 (m(CexZr0.9-xLa0.1O1.95):m(Al2O3) = 1; x = 0, 0.3, 0.5, 0.7, and 0.9) oxygen storage materials were prepared by the co-precipitation method. With these materials as supports, the Fe-based monolith catalysts were prepared by the impregnation method, and their catalytic activity for methane combustion at low concentration was investigated. The textural, structural, and redox properties of the catalysts were characterized by nitrogen adsorption-desorption, oxygen storage capacity (OSC) measurements, X-ray diffraction (XRD), and H-2-temperature-programmed reduction (H-2-TPR). The results of the activity test showed that the catalyst activity was the best when x = 0.7 and methane started to convert at 465 degrees C and converted completely at 615 degrees C on the catalyst at V(CH4) = 1% and GHSV = 50 000 h(-1). The nitrogen adsorption-desorption and OSC results showed that the CexZr0.9-xLa0.1O1.95-Al2O3 oxygen storage materials had high OSC, high surface area, and good thermal stability. The XRD results showed that when x = 0.5 and 0.7, the Fe-based catalysts had the best thermal stability and existed in a CexZr0.9-xLa0.1O1.95-Al2O3 solid solution. H-2-TPR results showed that at x = 0.7 the catalyst was most easily to be reduced.