Low-temperature catalytic oxidation of CO over highly active mesoporous Pd/CeO2–ZrO2–Al2O3 catalyst

Abstract

Mesoporous nano Pd/CeO₂, Pd/CeO₂–ZrO₂ and Pd/CeO₂–ZrO₂–Al₂O₃ catalysts were prepared via a soft template-assisted hydrothermal method and employed in low-temperature catalytic CO oxidation. Almost 100% of CO conversion could be obtained by the optimal Pd/CeO₂–ZrO₂–Al₂O₃ catalyst at 60 °C. Addition of Zr and Al into Pd/CeO₂ lead to an increase of the pore volume, average size of mesopores, the surface Ce³⁺/Ce⁴⁺ atomic ratios and O_adsorbed/O_lattice, while the activation energy (E_a) decreased in the order Pd/CeO₂ (50.4 kJ mol⁻¹) > Pd/CeO₂–ZrO₂ (40.7 kJ mol⁻¹) > Pd/CeO₂–ZrO₂–Al₂O₃ (32.4 kJ mol⁻¹). The low-temperature CO catalytic conversion increased with the decreased activation energy (E_a).