Composite material, for storing nitrogen oxides produced from moist exhaust streams from mobile and stationary combustion engines, comprises carrier material with finely divided X-ray amorphous layer

摘要

Composite material comprises a carrier material having a finely divided X-ray amorphous layer made of MnOy in an amount of 3-90 wt.% (where y = 1.6-2.0) on its outer surface. The composite has an adsorptivity for NOx in the temperature range of 20-550 deg C and a desorptivity for NOx in the temperature range of 200-800 deg C. An Independent claim is also included for a process for the production of a composite material comprising adding a solution of a water-soluble manganese (II) salt and an oxidizing solution selected from permanganate solutions and H2O2 solutions to carrier material present in the aqueous phase and calcining the solid produced at 200-700 deg C.