摘要:
A coating dispersion is shown for the production of catalysis-promoting coatings on an inert, structure-reinforcing element. The solids of the dispersion are present in various particle fractions and lead to a relatively rough coating surface with improved exchange between the exhaust gas and the catalyst surface. This results in improved heat-up behavior of the catalyst.
摘要:
A coating dispersion is shown for the production of catalysis-promoting coatings on an inert, structure-reinforcing element. The solids of the dispersion are present in various particle fractions and lead to a relatively rough coating surface with improved exchange between the exhaust gas and the catalyst surface. This results in improved heat-up behavior of the catalyst.
摘要:
A monolithic or honeycomb-catalyst, in particular for purifying the exhaust gases of internal-combustion engines, composed of an inert ceramic or metallic support traversed by parallel flow channels, a layer disposed thereon and composed of catalysis-promoting metal oxide and a catalytically active component supported by the metal oxide, wherein the concentration of the catalysis-promoting metal oxide increases from the periphery to the central axis of the support. Alternatively, the catalysis-promoting metal oxide is essentially equally distributed between central axis and periphery of the support, but concentration of catalytically active component increases from the central axis to the periphery of the support.
摘要:
A catalyst support for detoxifying the exhaust gases of alcohol fueled internal combustion engines contains, besides rare earth metal oxides and palladium, molybdenum silicide on active aluminum oxide in order to improve the conversion of noxious substances and the start up behavior.
摘要:
A catalyst for purifying the exhaust gases of internal combustion engines by means of oxidation and reduction with a reduced tendency to store sulfur oxides and to emit H.sub.2 S contains active Al.sub.2 O.sub.3 as carrier which is charged with CeO.sub.2 and optionally with ZrO.sub.2 as well as with platinum, and/or palladium, and optionally rhodium and also contains in addition 0.7 to 20% by weight B.sub.2 O.sub.3 relative to Al.sub.2 O.sub.3.
摘要翻译:通过氧化和还原的方式来净化内燃机废气的催化剂具有降低的存储硫氧化物的倾向并且排出H 2 S的催化剂,其含有作为载体的活性Al 2 O 3作为载体,其中CeO 2和任选地含有ZrO 2以及铂,并且 /或钯,和任选的铑,并且还相对于Al 2 O 3还含有0.7至20重量%的B 2 O 3。
摘要:
An oxidizing and/or reducing exhaust gas purification catalyst with a reduced tendency to emit H.sub.2 S contains active Al.sub.2 O.sub.3 as carrier which is charged with CeO.sub.2 and optionally ZrO.sub.2 as well as Pt, Pd and/or Rh and, in addition, 0.1 to 40% by weight ZnO relative to Al.sub.2 O.sub.3.
摘要翻译:具有降低排放H 2 S的趋势的氧化和/或还原废气净化催化剂含有作为载体的活性Al 2 O 3作为载体,其被加入CeO 2和任选的ZrO 2以及Pt,Pd和/或Rh,另外还含有0.1至40% 重量ZnO相对于Al2O3。
摘要:
A catalyst for the selective reduction of nitrous oxide with ammonia contains, in addition to titanium oxide as component (A), at least one oxide of W, Si, B, Al, P, Zr, Ba, Y, La, Ce and at least one oxide of Y, Nb, Mo, Fe, Cu as component (B), whereby the atomic ratio between the elements of components (A) and (B) amounts to 1:0.001 up to 1. The catalyst can be obtained by kneading reactive titanium oxide with a high specific surface of predominantly anatase with the substances of component (B) or their preliminary stages, adding processing agents, winding up with a homogeneous kneaded mass, extruding the latter, drying the extrudate and calcining in air at 300.degree.-800.degree. C.
摘要:
A device for the continuous measurement of the ammonia concentration in gases in the ppm range includes a columnar absorption vessel (1) with a hemispherical bottom (4). The bottom of the column includes an overflow (3) and an outlet (5). The gas introduction pipe (7,8) empties above the bottom (4) and below a sieve bottom (6) arranged in the column (1). A packing material (10) rests on the sieve bottom (6), which packing (10) essentially fills the absorption column (1). A cooling part (11) extends from the absorption column (1). The cooling part (11) includes a cooling zone (15) and a gas collection space (16) above it with a closable connection piece (13). A pipe (14), which may include a serrated crown on each end, runs from the gas collecting space (16) downward in a cooled manner to the packing 10. The liquid absorption agent is introduced through a lateral connection piece (18) into the gas collection space (16). For the measurement of ammonia concentration, a certain volume flow of the gas to be measured is washed in a countercurrent flow with the absorption agent, and the NH.sub.3 content is determined in a part of the ammonia containing absorption agent. The volume flow rate of the absorption agent and of the gas from which NH.sub.3 has been removed is measured (the latter being dried), and the ammonia concentration is thereby calculated.
摘要:
A method for the removal of nitrogen oxides contained in exhaust gases of an optionally fluctuating composition with a temperature of 0.degree.-600.degree. C. by means of catalytic reduction at a preselected stoichiometric ratio between the concentration of reducing agent and the concentration of nitrogen oxide in which the reducing agent is dosed in a pulsed manner.
摘要:
A zeolite catalyst and a method for reduction of nitrogen oxides present in waste gas streams is described. The method includes mixing the waste gas containing nitrogen oxides with ammonia. At an elevated temperature, this mixture is passed over a zeolite catalyst. Preferably, the zeolite catalyst is in a monolithic or honeycomb form. The zeolite catalyst includes one or more of the following subgroup metals: copper, iron, molybdeum and cerium. The zeolite catalysts made in accordance with this invention show better conversion of nitrogen oxides and longer life than known catalysts.