Next-Generation Polymer-Electrolyte-Membrane Fuel Cells Using Titanium Foam as Gas Diffusion Layer

In spite of their high conversion efficiency and no emission of greenhouse gases, polymer electrolyte membrane fuel cells (PEMFCs) suffer from prohibitively high cost and insufficient life-span of their core component system, the membrane electrode assembly (MEA). In this paper, we are proposing Ti foam as a promising alternative electrode material in the MEA. Indeed, it showed a current density of 462 mA cm^–2, being ca. 166% higher than that with the baseline Toray 060 gas diffusion layer (GDL) (278 mA cm^–2) with 200 ccm oxygen supply at 0.7 V, when used as the anode GDL, because of its unique three-dimensional strut structure promoting highly efficient catalytic reactions. Furthermore, it exhibits superior corrosion resistance with almost no thickness and weight changes in the accelerated corrosion test, as opposed to considerable reductions in the weight and thickness of the conventional GDL. We believe that this paper suggests profound implications in the commercialization of PEMFCs, because the metallic Ti foam provides a longer-term reliability and chemical stability, which can reduce the loss of Pt catalyst and, hence, the cost of PEMFCs

Realization of Both High-Performance and Enhanced Durability of Fuel Cells: Pt-Exoskeleton Structure Electrocatalysts

Core–shell structure nanoparticles have been the subject of many studies over the past few years and continue to be studied as electrocatalysts for fuel cells. Therefore, many excellent core–shell catalysts have been fabricated, but few studies have reported the real application of these catalysts in a practical device actual application. In this paper, we demonstrate the use of platinum (Pt)-exoskeleton structure nanoparticles as cathode catalysts with high stability and remarkable Pt mass activity and report the outstanding performance of these materials when used in membrane-electrode assemblies (MEAs) within a polymer electrolyte membrane fuel cell. The stability and degradation characteristics of these materials were also investigated in single cells in an accelerated degradation test using load cycling, which is similar to the drive cycle of a polymer electrolyte membrane fuel cell used in vehicles. The MEAs with Pt-exoskeleton structure catalysts showed enhanced performance throughout the single cell test and exhibited improved degradation ability that differed from that of a commercial Pt/C catalyst

Surface Structures and Electrochemical Activities of PtRu Overlayers on Ir Nanoparticles

PtRu overlayers were deposited on carbon-supported Ir nanoparticles with various Pt:Ru compositions. Structural and electrochemical characterizations were performed using transmission electron microscopy (TEM), X-ray diffraction, high-resolution powder diffraction (HRPD), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV), and CO stripping voltammetry. The PtRu overlayers were selectively deposited on the Ir nanoparticles with good uniformity of distribution. As a result, the PtRu utilization of the present samples was higher than that of PtRu/C. The mass-specific activities for methanol oxidation were also significantly higher. Single-cell performance using the Pt₂Ru₁ overlayer sample as an anode catalyst was slightly higher than that obtained using commercial PtRu/C despite the fact that the PtRu anode loading for Pt₂Ru₁/Ir/C was only 42% of that of PtRu/C