Development of highly active PdO-promoted CeO2-SiO2-Bi2O3/γ-Al2O3 inorganic catalysts for methane combustion

We herein report the preparation of αwt%PdO/16wt%Ce(1−x−y)SixBiyO2−δ/γ-Al2O3 (PdO/CS(x)Bi(y)/Al2O3) for application in the methane combustion reaction at low temperatures. The introduction of SiO2 into the CeO2 co-catalyst improved the specific surface area and acid–base properties of the catalyst to enhance its potential for application as an exhaust catalyst. In addition, the incorporation of Bi2O3 into the CeO2-SiO2 co-catalyst confirmed that the oxygen storage capacity and oxidation properties of PdO, which is known to exhibit a high oxidation capability toward methane, were enhanced for PdO/CS(x)Bi(y)/Al2O3. The highest catalytic activity was obtained for the 10wt%PdO/16wt%Ce0.85Si0.08Bi0.07/γ-Al2O3 catalyst, which exhibited a methane conversion of 88% at 500 °C.