| abstract |
An exhaust gas containing nitrogen oxides and particulate matter is cleaned by using an exhaust gas cleaner including a heat-resistant, porous filter; a porous ceramic powder layer formed on the filter; and a catalyst supported by the ceramic powder layer, the catalyst consisting essentially of (a) at least one of alkali metal elements, (b) cobalt and/or manganese, (c) vanadium, and (d) at least one of rare earth elements, whereby the nitrogen oxides are reduced by the particulate matter in the exhaust gas serving as a reducing agent. |