Abstract
Abstract The direct methanol fuel cell (DMFC) has good energy conversion efficiency, convenience of carrying methanol, capability of long-term power supply, and simple operating system.It is also important to be able to operate at the room temperature for daily use for portable electronic devices. Full stack DMFC was fabricated with the atomic layer Pt shell-Ru core nanocatalysts deposited on CNT and was tested for its performance. Polyol reduction method was used to synthesize the core-shell nanocatalysts. The slurry of ethanol solution containing some remaining polyvinylpyrrolidone and the nanocatalysts was coated on FTO glasses for testing with the electrochemical surface area (ECSA) and the methanol oxidation current density was measured by three-pole cyclic voltammetry method.It is found that the Ru core Pt shell nanocatalyst has a smallest open circuit potential and the largest I f /I b ratio as compared with pure Pt and RuPt alloy nanocatalysts. The core-shell catalyst has much better catalytic durability and structural stability than the RuPt alloy catalyst. The DMFC assemblies fabricated with four with different catalysts, Pt, RuPt alloy, Pt shell -Ru core at Pt/Ru=1.5 and Pt shell -Ru core at Pt/Ru=2.0, with a loading about 0.5 mg cm-2 were measured by 850E full cell test system. It is found that the DMFC containing the Pt shell /Ru core at Pt/Ru=2.0 has the highest output power density of 35 mW/cm2 and output current density of 245 mA/cm2 under 0.1 Volt condition among the four types of nanocatalysts.The performance of the Pt shell -Ru core at Pt/Ru=1.5 is very close to the Pt shell /Ru core at Pt/Ru=2.0 and it could be become the highest in term of the loaded amounts of nanocatalysts. It is concluded that the DMFC fabricated with atomic layer Pt shell-Ru core nanocatalysts out perform the PtRu alloy nanocatalysts not just in half cell tests but also in full stack DMFC tests.