| 摘要 |
PURPOSE: A preparation method of high performance Pa-Rh three way catalyst having low palladium content is provided to obtain particularly excellent purification effect of nitrogen oxides even when small quantities of palladium and rhodium are used and substantially reduce content of palladium and rhodium. CONSTITUTION: In a preparation method of Pa-Rh three way catalyst comprising a step (a) of impregnating alumina with palladium solution, and reducing the alumina impregnated with the palladium solution by thermal fixation; a step (b) of impregnating alumina with rhodium solution, and reducing the alumina impregnated with the rhodium solution using reducing agent; a step (c) of obtaining catalyst slurry by reacting the reduction resulting material with cerium dioxide; and a step (d) of preparing palladium three way catalyst by coating the catalyst slurry on a ceramic monolith support, the preparation method of high performance Pa-Rh three way catalyst having low palladium content is characterized in that the step (c) comprises the processes of preparing first catalyst slurry by 30 to 40 g/L of the cerium dioxide and cerium-zirconium complex oxide (Ce·Zr)O2 to the total apparent volume of the support, adding 5 to 7 g/L praseodymium dioxide to the total apparent volume of the support and adding a mixed solution of palladium and rhodium to the mixture; and additionally adding 40 to 45 g/L of (LaCe)(FeCo)O3 or (LaSr)(FeCo)O3 that is a metal oxide (perovskite) to the prepared first catalyst slurry so that the catalyst slurry of the step (c) is prepared.
|
