Hierarchical Nanostructured Pt8Ti-TiO2/C as an Efficient and Durable Anode Catalyst for Direct Methanol Fuel Cells

A catalyst for the electrochemical oxidation of methanol in direct methanol fuel cells (DMFCs) comprising Pt 8 Ti intermetallic nanoparticles dispersed in carbon nanorods (Pt 8 Ti-TiO 2 /C) is presented. The catalyst consists of Pt 8 Ti and rutile TiO 2 nanoparticles dispersed in nitrogen-doped carbon hierarchical nanostructures. The Pt 8 Ti-TiO 2 /C catalyst showed a 50 mV positive onset potential and 10 times higher specific activity than a commercial Pt/C catalyst. Using a half-cell experiment, we show that Pt 8 Ti intermetallic nanoparticles greatly enhance the methanol oxidation activity and durability in comparison to a Pt/C commercial catalyst. More importantly, a DMFC anode constructed with Pt 8 Ti-TiO 2 /C catalyst showed 4.6 times higher power density than a commercial Pt/C catalyst at 0.35 V and 333 K. Additionally, the Pt 8 Ti-TiO 2 /C catalyst displayed superior durability in comparison to the Pt/C catalyst. Pt 8 Ti-TiO 2 /C showed an electrochemical surface area decay of 23% at the end of 3000 CV cycles, whereas the Pt/C catalyst showed a more rapid decay of 90% at the end of 3000 CV cycles. The excellent stability of the Pt 8 Ti-TiO 2 /C catalyst during the accelerated durability stability test (AST) can be attributed to the stability of the rutile TiO 2 support, which is chemically resistant in the acidic electrolyte medium. The chronoamperometry and AST durability results confirmed that the Pt 8 Ti-TiO 2 /C hierarchical catalyst exhibited better stability than the pure Pt/C catalyst, suggesting that Pt 8 Ti-TiO 2 /C could be a promising anode catalyst in DMFCs.