oa Next generation polymer electrolyte membrane fuel cells

Polymer electrolyte membrane (PEM) fuel cell technology is one of the most promising alternative energy systems for an environmentally friendly, sustainable energy economy. Among the various types of fuel cells, PEM fuel cells are expected to be a dominant technology in the near future because they can operate with various types of energy carriers including hydrogen, ethanol, and methanol, run at relatively low temperatures (~80ºC). Fuel cells are suited for automotive applications where quick startup is required and can vary their output quickly to meet changes in power demand. Polymer electrolyte-based fuel cells require an expensive platinum (Pt) catalyst, which raises the cost of the fuel cell. PEM fuel cells can be cost effective to eliminate undesired chemical reactions during operation and to prevent degradation in performance over time however, new breakthroughs in fundamental materials technologies are essential. Nanoscale science and technology offer new opportunities to develop novel catalyst-electrode structures with dramatically improved performance. The review paper presents a new nanostructured PEM fuel cell electrode design comprised of a single layer carbon-free catalyst nanorods array with extremely low Pt loadings, controlled porosity, ideal alloy compositions, and with preferred crystal orientations for enhanced oxygen reduction. Glancing angle deposition (GLAD) process can be used for the growth of nanorods array for low Pt loading electrodes. Novel catalyst materials can significantly enhance the electrochemical reaction in fuel cell electrodes and as a result will reduce the amount of hydrogen needed for long-range transportation which would be highly desirable.