Highly stable PtRuTiOx/C anode electrocatalyst for direct methanol fuel cells

In the present investigation, PtRuTiOx/C electrocatalyst was prepared by a modified polyol synthesis method and the as-prepared electrocatalyst was treated under the reductive atmosphere (30 vol% H-2 in Ar) at 500 degrees C for 2 h (denoted as PtRuTiOx/C-500) to enhance the interaction between the metal particles and the support. For comparison, the commercial PtRu/C electrocatalyst was also treated by the same procedure as PtRuTiOx/C (denoted as PtRu/C-500). Transmission electron microscopy results indicated that PtRuTiOx/C electrocatalyst exhibited not only a uniform dispersion and narrow size distribution with a smaller particle size, but also excellent stability during the thermal treatment. In contrast, the commercial PtRu/C electrocatalyst is not stable during the thermal treatment and the metal particles greatly agglomerated. The results of CO-stripping voltammetry, single direct methanol fuel cell tests and life-time test jointly showed that PtRuTiOx/C-500 had better durability than commercial PtRu/C while keeping a desirable activity toward methanol electro-oxidation, which may be attributed to the addition of titanium oxide that improved the interaction between noble metal particles and the support. (C) 2006 Elsevier B.V. All rights reserved