| 摘要 |
To overcome the problem of a conventional catalyst and to provide an exhaust gas purifying catalyst that meets the requirement concerning Hg oxidation activity and SO 2 oxidation activity; i.e., an exhaust gas purifying catalyst which specifically reduces percent SO 2 oxidation, while maintaining percent Hg oxidation at a high level. The invention provides an exhaust gas purifying catalyst which comprises a composition containing oxides of (i) titanium (Ti), (ii) molybdenum (Mo) and/or tungsten (W), (iii) vanadium (V), and (iv) phosphorus (P), wherein the catalyst contains Ti, Mo and/or W, and V in atomic proportions of 85 to 97.5 : 2 to 10: 0.5 to 10, and has an atomic ratio of P/(sum of V and Mo and/or W) of 0.5 to 1.5, and an exhaust gas purifying method comprising exposing an exhaust gas containing a nitrogen oxide (NO x ) and metallic mercury (Hg) to the catalyst in the presence of ammonia as a reducing agent, to thereby perform reduction of NO x contained in the exhaust gas and oxidation of metallic mercury (Hg) contained in the exhaust gas. |
