(19)

(11)

EP 1 633 677 A2

(12)

(88) Date of publication A3: 20.01.2005 (43) Date of publication: 15.03.2006 Bulletin 2006/11 (21) Application number: 04729673.6 (22) Date of filing: 27.04.2004

(51) International Patent Classification (IPC):  C01B 21/26(1968.09) (86) International application number: PCT/GB2004/001785 (87) International publication number: WO 2004/096703 (11.11.2004 Gazette 2004/46)

(84) Designated Contracting States: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PL PT RO SE SI SK TR (30) Priority: 29.04.2003 GB 0309747 (71) Applicant: JOHNSON MATTHEY PUBLIC LIMITED COMPANY London SW1Y 5BQ (GB)

(72) Inventors: Axon, Sean Alexander Cleveland TS16 0GJ (GB) Coupland, Duncan Roy High Wycombe, Buckinghamshire HP11 1EA (GB) Foy, James Richard Stockton on Tees, Cleveland TS17 0XR (GB) Ridland, John Durham, County Durham DH1 5GL (GB) Wishart, Ian Carmichael Aston Tirrold, Oxfordshire OX11 9DD (GB) (74) Representative: Ridland, John  Johnson Matthey Catalysts P.O. Box 1 Belasis Avenue GB-Cleveland TS23 1LB GB-Cleveland TS23 1LB (GB)