Catalytically active material and catalytic converter for the selective catalytic reduction of nitrogen oxides

摘要

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 (1) made of a zeolite exchanged with one or more transition metals or a zeolite-like compound exchanged with one or more transition metals. The core of the catalytically active material is encased by a shell (2), which is made of one or more oxides selected from silicon dioxide, germanium dioxide, aluminum oxide, titanium oxide, tin oxide, cerium oxide, zirconium dioxide, and mixed oxides thereof.

主权项

1. A catalytically active material consisting of an inner core (1) and a shell (2) surrounding this core, wherein the core is formed from a zeolite or a zeolite-like compound which has been exchanged with one or more transition metals excluding nickel and chromium, and wherein the shell is formed from one or more oxides selected from the group consisting of silicon dioxide, germanium dioxide, aluminum oxide, titanium oxide, tin oxide, cerium oxide, zirconium dioxide and mixed oxides thereof.