Improvement of DMFC electrodes by carbon nanotubes

Fuel cells, the energy converting devices with a high efficiency and low (zero) emission, have been attracting more and more attention in recent decades due to high- energy demands, fossil fuel depletions, and environmental pollution throughout the world. For hydrogen gas fed fuel cells at their current technological stage, hydrogen production, storage, and transportation are the major challenges in addition to cost, reliability and durability issues. Direct methanol fuel cells (DMFCs), using liquid and renewable methanol fuel, have been considered to be favorable option in terms of fuel usage and feed strategies. Compared to hydrogen – fed fuel cells, which have a reforming unit, or low capacity in the hydrogen storage tank, the DMFC uses a liquid methanol fuel, which is easily stored and transported and simplifies the fuel cell system [1]. It has been recognized that the success of fuel cell technology depends largely on two key materials: the membrane and the electro catalyst. These two key materials are also directly linked to the major challenges faced in DMFCs, including (1) methanol crossover which can only be overcome by developing new membrane; (2) slow anode kinetics which can only be overcome by developing new anode catalysts. With regards to new DMFC anode catalysts, there are two major challenges, namely, the performance, including activity, reliability and durability, and cost reduction.