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How Nanotechnology is Improving the Hydrogen Fuel Cell

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The hydrogen fuel cell must be able to handle the explosive properties of hydrogen while making a good power source. There are many advances in nanotechnology that are improving the efficiency of the fuel cell, making it more affordable and accessible to people in developing nations. Many envision that vehicles of the future will be powered by renewable hydrogen, whose exhaust is pure water rather than the dangerous CO2 emissions. This review gives insight into what is happening on the nano scale for the improvement and advancement of the fuel cell, making it more accessible to the developing world.

How nanotechnology is improving the hydrogen fuel cell[edit]

Hydrogen fuel cells basically “converts the chemicals hydrogen and oxygen into water, and in the process it produces electricity” . A good picture of the fuel cell is available from [1]. Safer fuel cells are being developed using nanotechnology advances. One such technique uses single-walled carbon nanotubes to build more efficient hydrogen sensors . Researchers from the University of Wisconsin are working on a fuel cell with the potential of costing only $200 for materials, using AA batteries to make the nanowires. Kenneth Lux and Karien Rodriguez say: “Even the best electrocatalysts, on a flat surface, give only hundreds of microamps per square centimeter. What you really want is … to increase the surface area by orders of magnitude.”

"Lux and Rodriguez found their fuel channels ready-made in a commonly available, porous alumina filter costing only about $1. The filter is riddled with neat, cylindrical holes only 200 nanometers in diameter, and was already being used at their lab as a template for the growth of nanowires. Lux hit on the idea of creating nanowires in a platinum-copper alloy, then dissolving the copper by soaking the filter in nitric acid. In place of a solid nanowire, each hole was left with a porous platinum electrode. The partially dissolved wires are structurally complex, as befits their random nature, and have an enormous surface area for their size. To build a fuel cell, they fill the pores with acid. A sheet of electrolyte-loaded filter paper (or polymer-electrolyte) is placed between two of the nano-electrode arrays to carry off the hydrogen ions. Electrodes can then be placed anywhere on the outer surface of the sandwich, allowing the electrical connections to be easily configured. Stacks of these fuel cell arrays can be connected in series or parallel, to provide higher voltage or current respectively."

[1]

Pictures of their device are available at http://www.physorg.com/news11654.html.

Much research is being done through carbon nanotube synthesis to reduce the cost and increase the efficiency of fuel cells. Growing carbon nanotubes improves efficiency improves the utilization of the catalyst, and is therefore an improvement over carbon powders[2]. The multi-walled carbon nanotubes (MWNTs) make good electrical contact to the substrate (carbon paper). Although at the time of this research, Platinum particles were rather large, the researchers believed that decreased size in future would also increase the efficiency of the fuel cell . The “Single-Wall Carbon Nanotube-Based Proton Exchange Membrane Assembly for Hydrogen Fuel Cells” uses a platinum catalyst and is about 20% more efficient than the CFE/CB/Pt electrodes. This process improved the “performance of h2-based PEM fuel cells especially at higher pressures”. Research done with nano-sturctured hydrocarbon membranes in 2004 also helped to make the fuel cell more economical. The membrane, says Jim Balcom of PolyFuel Inc, “uses a lattice of nano-structured hydrocarbons to support a grid of conductive blocks through which protons flow as the cell generates electricity”. [3]

      The synthesis of hydrogen is also an area that has been improved upon using nano.............

Fuel Cell System Components[edit]

  • separator plates, current collector plates, membrane electrode assembly (MEA), gaskets, and possibly heaters.
  • All the fuel cell requires to generate electricity is hydrogen and oxygen gas, or air.
  • Semi-permeable membrane must allow H through while blocking other elements

Carbon nanotube based fuel cell components[edit]

  • platinum or other precious metal catalyst
  • carbon paper for growing nanotubes




web page: How Stuff Works, it’s good to know. How Fuel Cells Work by Karim Nice and Jonathan Strickland. Accessed 1/26/08. Available: http://auto.howstuffworks.com/fuel-cell.htm

web page: Nature, the Environment, and Stability News and Careers. Published August 01, 2007. Available: http://www.scenta.co.uk/Nature/1702164/nanotechnology-provides-safer-fuel-cells.htm

web page: Physorg.com: Science:Physics:Tech:Nano:News. Nano-scale fuel cells may be closer than we think, thanks to an inexpensive new manufacturing method. Nano Letters 6, 2006. Availalble: http://www.physorg.com/news11654.html

Article: Proton Exchange Membrane Fuel Cells with Carbon Nanotube Based Electrodes. Nano Letters. 2004, Vol. 4, No. 2, 345-348. Cheng Wang et. al. American Chemical Society, 2004.

Article: Single-Wall Carbon Nanotube-Based Proton Exchange Membrane Assembly for Hydrogen Fuel Cells. G. Girishkumar et. al. Langmuir 2005, 21, 8487-8949. American Chemical Society

Article: New membrane makes cheaper, stronger fuel cells. David Forman. SmallTimes. 17 Dec. 2004. Available: http://www.smalltimes.com/article/article_display.cfm?ARTICLE_ID=269761&p=109
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