Abstract
The present invention concerns a method for treating exhaust gases containing sulphur dioxides and NOx generated by a diesel or lean-burn engine comprising the steps of:(a) providing an acidic catalytic material comprising a noble metal-doped metal oxide material wherein the noble metal is present in the form of at least an oxidised species of rhodium in the exhaust gas system of said vehicle, and(b) exposing said exhaust gases to said catalytic material.