Sammensetning til bruk som NOx-felle, basert på mangan og alkalisk eller sjelden jordart, og anvendelse av denne forbehandling ev eksosgass

摘要

The invention concerns a composition usable as NOx trap in the treatment of exhaust gases. Said composition comprises a support and an active phase, and is characterised in that the active phase is based on manganese and at least another element A selected among alkaline-earths and rare earths, and it has or is capable of having a specific surface area of at least 10m<2>/g after being calcined for 8 hours at 800 DEG C. The support can be based on alumina or alumina stabilised with silicon, zirconium, barium or a rare earth; or based on silica or silica and titanium oxide.