Catalyst for the removal of pollutants from exhaust gases of lean-burn engines with ruthenium as active metal

摘要

The invention relates to a catalyst for exhaust-gas purification in lean-burn engines, the catalyst comprising at least ZrOSUB2 /SUBand/or Ce/Zr mixed oxide as support material and ruthenium as active metal, on its own or together with at least one further active metal selected from the precious metals group. Rare earth oxides and transition metals are used as promoters. The invention also comprises a method for purifying the exhaust gas from lean-burn engines in rich/lean and constant lean mode, in which a catalyst as defined above is used.