water recombination catalyst

[frenchero]

Hello everybody!

I am working on bubble formation issue in electroosmotic pumps. Those bubble are formed by water electrolysis on platinium electrode and I am searching for catalyst for water recombination compatible with biological applications to at least slow down the bubble formation process.

Would any one have an idea or a publication that xould help me? I have been looking for some but didn't find just chemical solutions.

Thank you very much.

[electroflow]

Has anyone figured out an answer to this question in the last couple years? I am trying to do exactly the same thing as the last post.

[Astronuc]

Water recombination? or recombination of H2 and O2 to form water?

If the latter, noble metals such as Pt or Rh are used to recombine free oxygen with free hydrogen. It's not clear that this is suitable for biological applications though.

[electroflow]

recombination of H2 and O2 to form water. I am not quite concerned about the biocompatibilty.

I am currently patterning the planar platinum catalyst/electrodes via e-beam deposition on a SiO2 wafer. The electrodes are 1mm wide and separated by about 25 microns. I have not been able to observe recombination when applying 10V. I would greatly appreciate any advice on the optimizing the parameters, in terms of the structure of the Pt catalyst (more surface area =>wider or use Pt black??), current density, and the structure of the electrodes.

[Astronuc]

At what temperature?

Soluble noble metals are effective in high temperature water. I suspect for biological applications and other applications, the temperatures are much lower.

[electroflow]

Room temperature, say 25C, excluding joule heating effects from the applied voltage. What temperatures are typically used?

[Astronuc]

The method with which I'm most familiar is employed at 215 to 285°C.

However, there maybe some modifications or other catalysts for lower temperature.

[electroflow]

Thanks Astronuc. Could you please point to any references which I can look up on that? Unfortunately, there is no way I can operate under such high temperatures. Is there any other parameter I could optimize?

[Astronuc]

Thanks Astronuc. Could you please point to any references which I can look up on that? Unfortunately, there is no way I can operate under such high temperatures. Is there any other parameter I could optimize? In the nuclear industry, noble metal injection was used to reduce the amount of hydrogen overpressure, which was an earlier strategy. I think the problem is that recombination efficiency decreases with temperature.

I'll look into my e-library, but possibly doping Pt/Rh with Au (or Ag) might work.

I'm also wondering if something organic, like one of the steps in the Krebs cycle would work.