(19)

(11)

EP 1 989 411 A1

(12)

(43) Date of publication: 12.11.2008 Bulletin 2008/46 (21) Application number: 07712976.5 (22) Date of filing: 01.03.2007

(51) International Patent Classification (IPC):  F01N 3/20(2006.01) (86) International application number: PCT/GB2007/050093 (87) International publication number: WO 2007/099372 (07.09.2007 Gazette 2007/36)

(84) Designated Contracting States: DE FR GB (30) Priority: 01.03.2006 GB 0604110 31.08.2006 GB 0617165 (71) Applicant: Johnson Matthey Public Limited Company London EC1N 8EE (GB)	(72) Inventors: GIDNEY, Jeremy Temple Cambridge, Cambridgeshire CB4 2AQ (GB) TWIGG, Martyn Vincent Cambridge, Cambridgeshire CB4 2AQ (GB) (74) Representative: Nunn, Andrew Dominic et al Johnson Matthey Technology Centre, Blount's Court, Sonning Common Reading, Berkshire RG4 9NH Reading, Berkshire RG4 9NH (GB)