摘要:
A method of catalytically reducing nitrogen oxides (NO.sub.x) and oxidizing hydrocarbons or carbon monoxide in exhaust gases of internal combustion engines or combustion power plants using a catalyst comprising a magnesium oxide/copper oxide/aluminum oxide spinel or a copper-impregnated copper oxide/aluminum oxide spinel.
摘要:
The present invention relates to a method for operating a catalyst for gases, especially for exhaust gases of stoichiometrically operated gasoline engines, wherein a catalyst is exposed to a gas stream and pollutants are catalytically converted. To improve the elimination of pollutants in the starting phase, hydrocarbons present in the gas are temporarily stored by the catalyst at temperatures below a response temperature of the catalyst, particularly below 200.degree. C., and preferably below 150.degree. C. The hydrocarbons are then released at temperatures above the response temperature and the pollutants, such as nitrogen oxides, are catalytically converted with reducing agents, such as hydrocarbons, carbon monoxide and mixtures thereof. The catalyst is a spinel, such as (MgCu)Al.sub.2 O.sub.4, which may also include a catalytically active species, such as WO.sub.3, V.sub.2 O.sub.5 and TiO.sub.2.
摘要翻译:本发明涉及一种用于操作气体催化剂,特别是用于化学计量操作的汽油发动机的废气的方法,其中催化剂暴露于气流并且污染物被催化转化。 为了改善起始阶段污染物的消除,存在于气体中的烃在催化剂的反应温度以下,特别是低于200℃,优选低于150℃的温度下,被催化剂临时储存。然后将烃 在高于响应温度的温度下释放并且诸如氮氧化物的污染物用还原剂如烃,一氧化碳及其混合物进行催化转化。 催化剂是尖晶石,例如(MgCu)Al 2 O 4,其还可以包括催化活性物质,例如WO 3,V 2 O 5和TiO 2。
摘要:
A catalyst and a method for producing the catalyst, for catalytic reduction of NO.sub.x and oxidation of hydrocarbons, the catalyst comprises a zinc, copper and aluminum spinel to which, at least one element selected from palladium, platinum, rhodium, ruthenium, osmium, iridium, rhenium and/or rare earth metals, such as lanthanum and cerium, vanadium, titanium, niobium, molybdenum, tungsten and/or salts thereof and/or oxides thereof has been added.
摘要:
A description is given of superconducting substances having a content of Bi, Sr, Ca and Cu, and of processes for their preparation from the metal oxides within a range which is specified by the overall composition Bi.sub.a (Sr,Ca).sub.b -Cu.sub.6 O.sub.x, where a=3-24 and b=3.23-24, with an Sr/Ca atomic ratio of 1:9-9:1 and a Bi:(Ca+Sr) atomic ratio of 0.3-1.5. The transition temperature is at least 60 K. The principal phase crystallizes in the orthorhombic system. The pure compounds Bi.sub.4 (Sr,Ca).sub.4 Cu.sub.2 O.apprxeq..sub.12 and Bi.sub.4 (Sr,Ca).sub.6 Cu.sub.4 O.apprxeq..sub.20.
摘要:
Black crystal compositions having the empirical composition Bi.sub.a Sr.sub.b Cu.sub.c O.sub.d are described where a+b+c=1, A=0.36-0.557, b=0.098-0.496, c=0.1-0.4 and d=approximately 1+a/2. These compositions have a superconducting transition temperature T.sub.c for superconductivity of greater than 20 K and contain a principal phase which crystallizes in the orthorhombic system. They can be prepared from the mixture of the oxides in the atomic ratio stated by heating to 700.degree.-1000.degree. C.
摘要翻译:其中a + b + c = 1,A = 0.36-0.557,b = 0.098-0.496,c = 0.1-0.4,d =约1 + a / 2,描述具有经验组成BiaSrbCucOd的黑色晶体组合物。 这些组合物具有大于20K的超导转变温度Tc,并且包含在正交系中结晶的主相。 它们可以通过加热至700°-1000℃的原子比由氧化物的混合物制备。