| abstract |
An internal combustion engine in which a main SO x trap catalyst (11) able to trap SO x contained in exhaust gas is arranged in an engine exhaust passage, and the exhaust passage downstream of the main SO x trap catalyst (11) is divided into a main exhaust passage (13) and a bypass passage (14) bypassing the main exhaust passage (13). An NO x storage catalyst (15) is arranged in the main exhaust passage (13), and an auxiliary SO x trap catalyst (16) is arranged in the main exhaust passage (13) upstream of the NO x storage catalyst (15). Normally, the exhaust gas is made to flow in the main exhaust passage (13). When regenerating the main SO x trap catalyst (11), the exhaust gas is made to flow through the bypass passage (14). |