Impact of soot-NSR catalyst contact depending on reactive gas composition on NOx storage

Interaction between a model soot (carbon black) and a model NOx storage reduction catalyst (Pt-Ba/Al2O3) is investigated as a function of the strength of the carbon-catalyst contact and the presence or not of H2O in the reactive gas flow. Experiments performed at laboratory scale, using a fixed bed reactor, revealed that the inhibiting effect of carbon on the NOx storage capacity (NSC) of the catalyst increases with the strength of carbon-catalyst contact and affects NOx adsorption on both Al sites and Ba sites, whereas the oxidative function of the catalyst (Pt sites) is not affected. In the presence of water in the reactive gas flow, it was observed that carbon prevents the inhibition of the oxidative function of the catalyst by H2O. On the other hand, the inhibiting effect of carbon on NSC decreases. Hence, a noncumulative effect of carbon and H2O impacts on NSC is observed. (c) 2015 American Institute of Chemical Engineers Environ Prog, 35: 14-19, 2016