Sometimes size doesn’t matter
Fuel cell research at Massachusetts Institute of Technology (MIT) has shown that size doesn’t matter but shape does. Scientists working on methanol powered fuel cells have discovered that the amount of platinum used for the electrodes didn’t matter as much as the actual shape of the platinum. By changing the surface of the catalyst, scientists have increased the efficiency of the fuel cells.
Associate Professor of Mechanical Engineering and Materials Science and Engineering Yang Shao-Horn, has led a team at MIT scientists researching improvements in fuel cell efficiency in the hopes of making fuel cells more affordable. Fuel cells are one of the cleanest ways of powering electronics. Since fuel cells don’t emit any greenhouse gases or other toxic substances, they seem like the ideal power source, but they are currently too expensive.
Platinum has been used for ethanol fuel cells electrodes for some time. Varying the amount of platinum in the electrodes didn’t show any consistent change in efficiency. However, Professor Shao-Horn’s group varied not the amount of the platinum being used but the surface of the platinum.
Rather than a smooth surface, the scientists created a rough surface similar to stair steps creating more surface area for chemical reactions to occur. Apparently the tiny stair step edges are easier for “atoms to form new bonds.” “This approximately doubled the electrode’s ability to catalyze oxidation of the fuel and thus produce electric current.”
Essentially the researchers “used platinum nanoparticles deposited on the surface of multi-wall carbon nanotubes.” Others have been using platinum nanoparticles as well but have only been varying the amount of platinum. MIT is the first to vary the surface structure. More research is expected to further increase the efficiency of the fuel cells thus making them more competitive with other sources of power like li-ion batteries.
The tiny platinum stair steps may prove to be the “stairway to heaven” for researchers looking to create better cheaper methanol fuel cells.
Related posts:
