Exhaust purification system

Abstract

An exhaust gas purification system provided with an NO X purification catalyst reducing the amount of use of precious metals and/or able to exhibit an NO X purification performance at a low temperature and/or in an oxidizing atmosphere and having an NO X purification performance even for an exhaust gas composition containing hydrocarbons and oxygen together with a low temperature and/or oxidizing atmosphere, that is, an exhaust gas purification system provided with an NO X purification catalyst provided in an exhaust gas passage and comprised of carrier particles on which nanoparticles in which gold atoms and nickel atoms are included in a state in close proximity are carried and an oxidation catalyst oxidizing hydrocarbons in exhaust gas at a position at an upstream side of the NO X purification catalyst.

1 - 5 . (canceled) 
     
     
         6 . A exhaust purification system provided with an NO x  purification catalyst provided in an exhaust gas passage and comprised of carrier particles on which nanoparticles of an alloy of gold atoms and nickel atoms in a state in close proximity are carried and an oxidation catalyst oxidizing hydrocarbons in exhaust gas at a position at an upstream side of the NO x  purification catalyst. 
     
     
         7 . An exhaust gas purification system as set forth in  claim 6 , wherein the nanoparticles have a size of 0.2 to 100 nm. 
     
     
         8 . An exhaust gas purification system as set forth in  claim 6 , wherein the carrier particles are metal oxide particles. 
     
     
         9 . An exhaust gas purification system as set forth in  claim 6 , further provided with a hydrocarbon absorbent that absorbs hydrocarbons in the exhaust gas at a position in the exhaust gas at a position in the exhaust gas passage at a further upstream side from the oxidation catalyst.