Activity of 12 catalysts of 2% or 5%Pt deposited (from H2PtCl6) on binary carriers like 10%TiO2(from Ti(i-Pr)(4))-on-SiO2 (or on Al2O3 or Al2O3-SiO2) and 5%TIO2/Al2O3, BET 90-460 m(2)/g, was studied at 200-800degreesC in terms of imols CO/(g(cat)-S) in relation to temperature, prereduction (preferably 1 h/400degreesC), and carrier type. At 800degreesC, the activities followed the descending type: 5%Pt/TiO2 > 5%Pt/5%TiO2/Al2O3 > 2%Pt/5%TiO2/Al2O3 > 5%Pt/10%TiO2/Sio(2) > 5%Pt/ 10%TiO2/Al2O3 > 2%Pt/10%TiO2/Al2O3 > 2%Pt/TiO2 > 5%pt/ 10%TiO2Al2O3-SiO2 > 2%Pt/10%TiO2/Al2O3-SiO2 > 2%Pt/ 10%TiO2/SiO2 > 5%Pt/SiO2 > 2%Pt/SiO2. As compared with pure SiO2, TiO2 as co-carrier enhanced the activity. With SiO2 as carrier, C deposited most extensively. In the reaction, CO2 Was faster consumed than CH4 and more CO was formed than H-2, In an 18-h long test, 2%Pt/SiO2 and 5%Pt/ 5%TiO2/Al2O3 lost 59 and 5% of activity, resp.