Direct methanol fuel cell anode catalyst proton current

PEM fuel cells use a solid proton-conducting polymer as the electrolyte at 50-125 °C. The cathode catalysts are based on Pt alone, but because of the required tolerance to CO a combination of Pt and Ru is preferred for the anode [8]. For low-temperature (80 °C) polymer membrane fuel cells (PEMFC) colloidal Pt/Ru catalysts are currently under broad investigation. These have also been proposed for use in the direct methanol fuel cells (DMFC) or in PEMFC, which are fed with CO-contaminated hydrogen produced in on-board methanol reformers. The ultimate dispersion state of the metals is essential for CO-tolerant PEMFC, and truly alloyed Pt/Ru colloid particles of less than 2-nm size seem to fulfill these requirements [4a,b,d,8a,c,66j. Alternatively, bimetallic Pt/Ru PEM catalysts have been developed for the same purpose, where nonalloyed Pt nanoparticles <2nm and Ru particles <1 nm are dispersed on the carbon support [8c]. From the results it can be concluded that a Pt/Ru interface is essential for the CO tolerance of the catalyst regardless of whether the precious metals are alloyed. For the manufacture of DMFC catalysts, in... 

H+) Produced by the dissociation of Hj at the anode to the cathode, (3) Prevention of the associated electron flow through the membranes forcing them to flow in the external circuit to the cathode to produce DC current, and (4) Support for the catalyst loaded on the electrodes. When Hj is replaced by methanol as a fuel in liquid form in direct methanol fuel cell (DMFC), the dissociation of methanol solution at the anode produces protons that are transported through the hydrated PEM to the cathode, where a reduction of O2 produces water in the presence of the protons. To qualify PEM for commercial application in PEMFC and DMFC, it should have a combination of properties including (Maiyalagan and Pasupathi 2010 Neburchilov et al. 2007 Nagarale et al. 2010) ... 

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