CATALYTIC COMBUSTION OF DIESEL PARTICULAT E MATTER(PM) ON TITANIUM-OXIDE SUPPORTED CATALYSTS

Catalytic combustion of particulate matter(PM) in Diesel engine exhaus t gas has been examined using various titanium(N) oxide supported cata lysts. A copper catalyst (Cu/TiO2(Cl)), especially derived from copper (IT) chloride, showed an excellent combustion activity among these cat alysts, although most of catalysts increased their combustion activiti es by use of chlorides as starting materials. XRD analyses revealed th at the formation of copper( II) chloride hydroxide (CuCl(OH)) is essen tial for the generation of active sites containing chlorine species. T his means that the formation of the active chloride species composed o f copper species will assist to promote the emergence of active oxygen species. The copper catalyst effectively worked under a simulated Die sel engine exhaust, suggesting that the active species are not so much poisoned by SO,. Since the PM combustion was not affected by the pres ence of SOF(Soluble Organic Fraction) and the soot seemed to be an amo rphous carbon, the ignition of solid by solid catalyst has to occur fo r the combustion, indicating that the key is the close contact of oxyg en species activated on the catalyst with PM and the active structure containing chlorine species is essential for the development of new ca talysts.