The new concept catalyst for diesel engine has been developed. When the exhaust temperature is low, SOF and HC are temporarily adsorbed by the adsorbent within the catalyst and are oxidized as the temperature rise. This is a different that the low-temperature oxidation activity is appeared by the noble metal loading of the catalyst. The process of this development have manifested as follows.
The coating material is important factor to govern the oxidation activity.
SOF is reduced by the coating material in low temperature less than 200
The coating material, which has low SO2 adsorbing rate suppress the sulfate formation at high temperature.
To reduce NOx in the diesel engine exhaust gas is possibility by utilizing adsorptive characteristics of the catalyst.