| 초록 |
In the sol-gel three-way catalysts, V and Zr was a good promoter to improve the durability under SO2 and enhance the thermal stability at high temperature, respectively. Extraordinary characteristics of high activity at low-temperature, improved thermal stability and enhanced durability against SO2 was established on the catalyst containing specific mole ratio of V/Zr = 0.36, Pd-V(2)-Zr(10)-Al2O3 catalyst, in which synergism between V and Zr was attributed to the formation of V-O-Zr bond in the tetrahedrally coordinated (M-O)3V=O species. By this synergism, the phase transformation from PdO, tetragonal ZrO2, gamma-Al2O3 and amorphous tetrahedrally coordinated (M-O)3V=O to highly dispersed PdO, monoclinic ZrO2, kappa-Al2O3 and microcrystalline octahedrally coordinated V2O5 species, were inhibited during the thermal aging.
|
