Sammensetninger benyttet som NOx-felle, basert på mangan og alkali eller jordalkali, og andvendelse av disse for behandling aveksosgass

摘要

The invention concerns compositions used as NOx trap, based on manganese and an alkaline or an alkaline-earth and their use for treating exhaust gases. Said compositions comprise a carrier and an active phase; and they are characterised in that the active phase is based on manganese and at least another element A selected among alkalines or alkaline-earths, the manganese and element A being chemically bound. Said compositions can be used in a process for treating gases to reduce nitrogen oxide emissions, as NOx traps, said gases being derived from internal combustion engines and in particular diesel engines or lean-burn engines.