Effect of BaO on Catalytic Activity of Pt-Rh TWC

The effect of BaO doping to the Pt-Rh catalysts on its three-way catalytic activity and water-gas transfer was investigated. The results show that the light-off temperatures of hydrocarbon and carbon monoxide and nitrogen oxides have little difference in the fresh catalysts. But after the hydrothermal-aged 5 h at 1000 ℃, the catalysts containing CeO2-ZrO2-BaO has lower light-off temperature and better catalytic activity than the catalysts containing BaO and CeO2-ZrO2. The catalysts were characterized by means of the temperature-programmed reduction （TPR） in the hydrogen and the temperature-programmed desorption （TPD） in the oxygen. It is confirmed that the presence of CeO2-ZrO2-BaO by co-precipitation can improve catalytic activity of catalysts.