Patent application number | Description | Published |
20110056187 | METHOD FOR DECREASING NITROGEN OXIDES IN HYDROCARBON-CONTAINING EXHAUST GASES USING AN SCR CATALYST BASED ON A MOLECULAR SIEVE - The invention relates to a process for treating diesel engine exhaust gases comprising nitrogen oxides (NO | 03-10-2011 |
20110142737 | SELECTIVE CATALYTIC REDUCTION OF NITROGEN OXIDES IN THE EXHAUST GAS OF DIESEL ENGINES - A catalyst and a process for selective catalytic reduction of nitrogen oxides in diesel engine exhaust gases with ammonia or a compound decomposable to ammonia are described. The exhaust gas to be cleaned is passed together with ammonia or a compound decomposable to ammonia over a catalyst which comprises a zeolite or a zeolite-like compound containing 1-10% by weight of copper, based on the total weight of the zeolite or of the zeolite-like compound, and a homogeneous cerium-zirconium mixed oxide and/or a cerium oxide. The zeolite used or the zeolite-like compound used is selected from the group consisting of chabazite, SAPO-34, ALPO-34 and zeolite-β. | 06-16-2011 |
20130121902 | NOVEL MIXED OXIDE MATERIALS FOR THE SELECTIVE CATALYTIC REDUCTION OF NITROGEN OXIDES IN EXHAUST GASES - The invention relates to the use of mixed oxides made of cerium oxide, zirconium oxide, rare earth sesquioxide and niobium oxide as catalytically active materials for the selective catalytic reduction of nitrogen oxides with ammonia or a compound that can decompose to form ammonia in the exhaust gas of internal combustion engines in motor vehicles that are predominantly leanly operated, and to compositions or catalysts which contain said mixed oxides in combination with zeolite compounds and/or zeolite-like compounds and are suitable for the denitrogenation of lean motor vehicle exhaust gases in all essential operating states. | 05-16-2013 |
20130156668 | CATALYST FOR REMOVING NITROGEN OXIDES FROM THE EXHAUST GAS OF DIESEL ENGINES - The invention relates to a catalyst for removal of nitrogen oxides from the exhaust gas of diesel engines, and to a process for reducing the level of nitrogen oxides in the exhaust gas of diesel engines. The catalyst consists of a support body of length L and of a catalytically active coating which in turn may be formed from one or more material zones. The material zones comprise a copper-containing zeolite or a zeolite-like compound. The materials used include chabazite, SAPO-34, ALPO-34 and zeolite β. In addition, the material zones comprise at least one compound selected from the group consisting of barium oxide, barium hydroxide, barium carbonate, strontium oxide, strontium hydroxide, strontium carbonate, praseodymium oxide, lanthanum oxide, magnesium oxide, magnesium/aluminum mixed oxide, alkali metal oxide, alkali metal hydroxide, alkali metal carbonate and mixtures thereof. Noble metal may optionally also be present in the catalyst. | 06-20-2013 |
20130189172 | CATALYST FOR REMOVING NITROGEN OXIDES FROM THE EXHAUST GAS OF DIESEL ENGINES - The invention relates to a catalyst for removal of nitrogen oxides from the exhaust gas of diesel engines, and to a process for reducing the level of nitrogen oxides in the exhaust gas of diesel engines. The catalyst consists of a support body of length L and of a catalytically active coating which in turn may be formed from one or more material zones. The material zones comprise selectively catalytically reductive (SCR-active) mixed oxide consisting of cerium oxide, zirconium oxide, rare earth sesquioxide and niobium oxide and optionally tungsten oxide. In addition, the material zones comprise at least one compound selected from the group consisting of barium oxide, barium hydroxide, barium carbonate, strontium oxide, strontium hydroxide, strontium carbonate, praseodymium oxide, lanthanum oxide, magnesium oxide, mixed magnesium/aluminum oxide, alkali metal oxide, alkali metal hydroxide, alkali metal carbonate and mixtures thereof. Noble metal may optionally also be present in the catalyst. | 07-25-2013 |
20130266497 | COPPER/CHABAZITE-BASED CATALYST WITH IMPROVED CATALYTIC ACTIVITY FOR REDUCTION OF NITROGEN OXIDES - The present invention relates to a process for improving the catalytic activity of a copper-promoted zeolitic catalyst with chabazite structure, to a copper-promoted zeolitic catalyst with chabazite structure and to a process for reducing nitrogen oxides in an offgas stream. | 10-10-2013 |
20130336863 | SCR CATALYTIC CONVERTER HAVING IMPROVED HYDROCARBON RESISTANCE - A catalyst for the selective catalytic reduction of nitrogen oxides in diesel engine exhaust gases using ammonia or a precursor compound decomposable to ammonia is described. The catalyst comprises two superposed coatings applied to a support body, of which the first coating applied directly to the support body comprises a transition metal-exchanged zeolite and/or a transition metal-exchanged zeolite-like compound, and effectively catalyzes the SCR reaction. The second coating has been applied to the first coating so as to cover it on the exhaust gas side. It is configured so as to prevent the contact of hydrocarbons having at least three carbon atoms present in the exhaust gas with the layer beneath, without blocking the passage of nitrogen oxides and ammonia to the first coating. The second coating may be formed from small-pore zeolites and/or small-pore zeolite-like compounds, and from suitable oxides, especially silicon dioxide, germanium dioxide, aluminum oxide, titanium dioxide, tin oxide, cerium oxide, zirconium dioxide and mixtures thereof. As well as the catalyst, routes for production thereof are described. | 12-19-2013 |
20130336866 | CATALYTICALLY ACTIVE MATERIAL AND CATALYTIC CONVERTER FOR THE SELECTIVE CATALYTIC REDUCTION OF NITROGEN OXIDES - The invention relates to a catalytically active material for reacting nitrogen oxides with ammonia in the presence of hydrocarbons. The material consists of an inner core ( | 12-19-2013 |
20140041366 | CATALYTIC CONVERTER FOR THE SELECTIVE CATALYTIC REDUCTION OF NITROGEN OXIDES IN THE EXHAUST GAS OF DIESEL ENGINES - The present invention relates to a catalytic converter which comprises a molecular sieve and a mixed oxide, and to a method for the selective catalytic reduction of nitrogen oxides in exhaust gases of diesel engines. | 02-13-2014 |