Pd loaded mesoporous ZrO₂-TiO₂ composite and its CO catalytic oxidation property

Mesoporous Pd/ZrO₂-TiO₂ and PdCu/ZrO₂-TiO₂ composites with high CO catalytic oxidation performance were successfully synthesized by using mesoporous ZrO₂-TiO₂ as catalyst support. Both XRD and TEM results indicated that the Pd or Cu species could be homogeneously dispersed in the ZrO₂-TiO₂ support. The effects of different factors on the CO oxidation property were investigated, including the different kinds of catalyst supports, preparation methods and catalytic promoters. It was found that mesoporous ZrO₂-TiO₂ as the catalyst support exhibited higher catalytic performance for CO oxidation than mesoporous Al₂O₃ or SBA-15. In addition, the low-temperature catalytic activity of Pd/ZrO₂-TiO₂ catalyst prepared by one-step route was greatly enhanced in comparison with traditional impregnation method. More importantly, the co-loaded PdCu/ZrO₂-TiO₂ catalyst via one-step process showed the optimal catalytic activity for CO oxidation, and the corresponding complete conversion temperature reduced to 170°C, which was attributed to the interaction between the Pd and Cu species according to the O₂-TPD analysis.