Remarkable improvement of yttrium on the activity and thermal stability of methane combustion over Pd/Ce-Zr/Al2O3 catalyst

The effects of Y addition to Pd/Ce-Zr/Al2O3 catalyst have been investigated for the combustion of methane. The supported Pd catalysts are characterized by XPS, TPR, TPO and TPSR techniques in order to study the oxidation/reduction properties. Activity tests in methane combustion show that addition of Y to Pd/Ce-Zr/Al2O3 catalyst remarkably promotes its low-temperature and total conversion activity. In addition, the introduction of Y also greatly suppresses deactivation of Pd/Ce-Zr/Al2O3 and endows Pd/Ce-Zr-Y/Al2O3 with higher thermal stability than Pd/Ce-Zr/Al2O3. The characterization results of catalysts indicate that the addition of Y to Pd/Ce-Zr/Al2O3 catalyst can effectively inhibit the decomposition of PdO particles and improve the reduction–reoxidation properties of the active PdO species, which increases the catalytic activity and thermal stability of the Pd/Ce-Zr/Al2O3 catalyst.