Recent advances in the understanding of the direct conversion of soot: and NO on Fe2O3 catalyst in diesel exhaust

This article reviews the fundamentals of the catalytic reaction of soot and NO in diesel exhaust to form N 2 and C0 2 focussing on the model catalyst Fe 2 O 3 . It was found out that the soot/NO reaction is a side reaction of the soot/O 2 conversion, in which the Fe 2 O 3 catalyst acts as oxygen pump transferring oxygen from the gas-phase via its surface to the soot. However, the catalyst is not directly involved in the soot/NO reaction other than increasing the number of C * sites. These sites were considered to be responsible for the NO reduction on the soot facilitating the dissociation of NO and formation of N 2 . Based on this mechanism a global-kinetic model was constructed.