The effects of potassium halides on catalytic activities of CeO2–K based catalysts for diesel soot oxidation

The CeO2–K catalysts loaded on porous alumina substrate have been produced by a new route. The potassium halides played an important role on the catalytic activity enhancement of CeO2 catalyst for soot oxidation. This improvement could partially originate from the catalytic production of CO by the potassium halides. Their effects on the catalytic activity promotion followed the order KF ∼ KCl > KBr > KI and their addition into CeO2 resulted in the CeO2–K catalysts with the lowest soot ignition temperatures of about 334, 335, 345 and 362 °C, respectively, at a loose soot/catalyst contact mode. Nevertheless, the CeO2 with addition of KCl behaved a better catalytic performance. It was also found that the catalysts have a CO2 absorption capability.