Sam.joo98 - 11-4-2015 at 03:47
Does anyone know how to make an apparutus that generates electricty with hydrogen and oxygen?
Metacelsus - 11-4-2015 at 05:04
Welcome to Sciencemadness.
The Energetic Materials subforum is to "Discuss the theory, preparation, and initiation of energetic materials."
If this post were more substantive, it would belong in Technochemistry, but as I see it now, it should be in Beginnings, or posted to the Short
Questions Thread.
As for the fuel cell, there are many different designs. I suggest you read the Wikipedia page.
deltaH - 11-4-2015 at 06:31
Sam.joo98, simply bubbling hydrogen and oxygen separately over short pieces of platinum wire immersed in an acidic solution will
generate electricity, albeit at very low power levels.
Using platinum with a larger surface area increases the power levels as the platinum is acting as a heterogeneous catalyst and its activity is
proportional to its surface area.
If you want higher power, you need to dramatically increase the surface area of the electrocatalyst. This is done by employing platinum nanoparticles
supported over a porous carbon support and are commercially available. At such high electrode chemical rates of reduction and oxidation, transport of
protons from the anode to the cathode becomes limiting, so commercially, porous ionic membranes that have channels of super acids are used, such as
Nafion (amongst other reasons).
The electrocatalyst powder is 'printed' as an ink together with a dispersed Nafion solution back to back to a thin sheet of Nafion membrane and
pressed. This is called a MEA (membrane electrode assembly) and is also commercially available individually. These in turn are clamped between
electrode plates of a inert electrical conductor, for example, graphite, that have microchannels cut into them to flow the gas over the surface of
the catalyst.
These can then be stacked to make large fuel cell stacks that are bolted together and require cooling due to inefficiencies and the very high power
levels in operation.
[Edited on 11-4-2015 by deltaH]
Sam.joo98 - 16-4-2015 at 02:12
thank you deltaH