On the activity and stability of Pt-K/Al2O3 LNT catalysts for diesel soot and NOx abatement

Abstract DPNR Pt-K/Al 2 O 3 catalyst has been studied for the simultaneous removal of soot and NO x , in the presence of both water and carbon dioxide. In particular, the effect of soot on the NO x storage activity and on the stability of Pt-K/Al 2 O 3 catalyst has been addressed. It has been found that: (i) the presence of soot decreases the NO x storage activity at any temperature in the range 250–350 °C; (ii) the stability of the adsorbed species is lower in the presence of soot; (iii) nitrates ad-species directly interact with soot and participate to the soot combustion; (iv) aged catalyst shows a lower storage capacity and a lower soot oxidation activity attributed to loss of K-active species.

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