Low-Temperature Combustion of CH4over CeO2–MOxSolid Solution (M = Zr4+, La3+, Ca2+, or Mg2+) Promoted Pd/γ–Al2O3Catalysts

Abstract

The catalytic behavior of Pd (2 wt%) catalysts supported on γ-Al2O3 and promoted with CeO2 − MOx(M = Zr4+, La3+, Ca2+, or Mg2+) solid solution was investigated for methane combustion. The results demonstrated that Pd/γ-Al2O3CeO2 MOx catalysts can be effective for the low-temperature catalytic combustion of methane and are comparable in activity to other conventional catalysts for this reaction. The XPS and XRD results indicated that an enhanced mobility of lattice oxygen induced by the perturbation of Ce–O lattice was responsible for an increased catalytic performance during oxidation reaction. The most active sites in the catalyst system involve contacts between Pd and the CeO2–MOx mixed oxide component. Meanwhile, pre-treatment conditions have significant effect on the catalytic activity in methane combustion.