Exhaust gas purification device for internal combustion engine

An exhaust gas purification device for an internal combustion engine, the exhaust gas purification device comprising:

• a NOx purification unit on which a NOx purification catalyst that is provided in an exhaust passage of the internal combustion engine, that captures, when exhaust gas flowing in is lean, NOx in the exhaust gas and that desorbs the captured NOx when the exhaust gas flowing in is rich so as to reduce and purify the exhaust gas is supported;
• an exhaust gas purification filter on which a particulate combustion catalyst that is provided in the exhaust passage on a downstream side of the NOx purification unit, that captures a particulate in the exhaust gas flowing in and that burns the captured particulate is supported;
• and
• an electronic control unit configured to perform control so as to enrich the exhaust gas flowing into the NOx purification catalyst and which heats the NOx purification catalyst to a predetermined temperature so as to desorb a sulfur component captured by the NOx purification catalyst,
• wherein the particulate combustion catalyst is supported on an Al2O3 carrier in a state where Ag and Pd are alloyed,
• an amount of Ag supported on the Al2O3 carrier is 1.2 to 2.5 g/L,
• an amount of Pd supported on the Al2O3 carrier is equal to or less than 0.7 g/L and
• a ratio Ag/Pd of the amount of Ag supported to the amount of Pd supported is 1.7 to 8.3.