| 초록 |
Automobiles exhaust harmful air pollutants such as CO, hydrocarbons (HCs), NOx and particulate matters (PMs). Accordingly, considerable researches on automotive catalysts for the total oxidation of CO and HCs have been conducted. Pd is well-known oxidation catalysts for removal of CO and HCs. Likewise, ceria is widely used as a support due to its catalytic activity on oxidation and it promotes dispersion of noble metal. It is demonstrated that reducible oxides supply lattice oxygen to supported metal, which improves redox property of catalysts. Also, oxygen adsorption occurs well on lattice defect, known as oxygen vacancy, assisting oxidative activity. Since automotive catalyst should undergo high temperature condition, sinter-resistant catalyst must be developed. The main purpose is to maintain the size of Pd through the aging by coating supported Pd nanoparticles with mesoporous CeO2. The suggested nanostructure can enhance thermal stability of the catalyst and it can also improve catalytic activity of Pd in CO and propylene oxidation, which is attributed to the synergistic interaction between Pd and CeO2. |
