Cerium based shells with palladium cores encapsulated: an efficient catalyst for carbon monoxide oxidation

Pd@Zr/CeO2 core-shell catalyst prepared by hydrothermal method was applied in CO oxidation reaction, exhibiting high CO oxidation activity at low temperature. XRD (X-ray diffraction) analysis demonstrated that the remarkable enhancement of catalytic performance was found to depend on the presence of more oxygen vacancies in the core-shell structure, which contributed higher content of and ready release of active oxygen species at low temperature, confirmed by H-2-TPR (temperature programed reduction) results. Interestingly, introducing a small amount of zirconium (0.5 wt.%) exhibited a significant improvement of catalytic activity because the introduction of Zr further improved the amount of crystal defects and promoted the migration of oxygen species.