| abstract |
The present invention relates to crystalline zeolites with an ERI/CHA intergrowth framework type and to a process for making said zeolites. The ERI content of the zeolites ranges from 10 to 85 wt.-%, based on the total weight of ERI and CHA. The zeolites may further comprise 0.1 to 10 wt.-% copper, calculated as CuO, and one or more alkali and alkaline earth metal cations in an amount of 0.1 to 5 wt.-%, calculated as pure metals. The process for making the zeolites with an ERI/CAH intergrowth framework type comprises a) the preparation of a first aqueous reaction mixture comprising a zeolite of the faujasite framework type, Cu-TEPA and a base M(OH), b) the preparation of a second aqueous reaction mixture comprising a silica source, an alumina source, an alkali or alkaline earth metal chloride, bromide or hydroxide, a quaternary alkylammonium salt and hexamethonium bromide, c) combining the two reaction mixtures, and d) heating the combination of the two reaction mixtures to obtain a zeolite with an ERI/CHA intergrowth framework type. The ERI/CHA intergrowth zeolite may subsequently be calcined. The zeolites according to the present invention are suitable SCR catalysts. |