CATALYST FOR THE TRANSFORMATION OF HYDROCARBONS AND THE REDUCTION OF NITROGEN OXIDES, METHOD FOR PRODUCING SAID CATALYST AND UTILIZATION OF THE CATALYST FOR THE CATALYSIS OF EXHAUST GASES FROM DIESEL ENGINES

摘要

A catalyst usable for transforming hydrocarbons and gases and for reducing nitrogen oxides comprises as essentially components of the active substance thorium oxide, in addition to LaCoO3. The catalyst comprises as ''wash coat'' oxidized ceramics and spinels of magnesium, aluminium, titanium and zircon oxide, enriched with ceroxide and lanthane oxide, as well as LaCoO3 previously prepared and dissolved in acid conditions. The body formed in the absence of the active substance LaCoO3 is used as combustion catalyst at high temperature, for example during heat generation from coal without emission of nitrogen oxides. A method and a device use the catalysts for the post combustion of exhaust gases from diesel engines in the excentric layers of the catalyst which adsorb the soot particles mainly during the starting phase, as well as in a honeycomb post combustion catalyst for the post combustion and reduction of nitrogen oxides in the output phase of the engine. The post combustion device, due to the stream flow direction may also act as exhaust silencer.