| 摘要 |
Provided is a method for extending a temperature range enabling combustion of high concentration hydrocarbon, or for rapidly supplying high temperature gas to a later stage catalyst. Provided is a method for purification of exhaust gas from an internal-combustion engine comprised by:
providing a temperature-raising catalyst for exhaust gas from an internal-combustion engine in an exhaust gas passage of the internal-combustion engine, along flow of said exhaust gas, at the upstream side of a purification catalyst for said exhaust gas; and introducing hydrocarbon in an amount of 1,000 to 40,000 ppm, as converted to methane, from the upstream side of the temperature-raising catalyst, wherein said temperature-raising catalyst has catalytically active components supported onto a refractory three-dimensional structure, wherein concentration of said components has a gradient such that said concentration gradually becomes lower from the inflow side toward the outflow side of said exhaust gas. |
