A new catalyst for splitting water into molecular oxygen
Download
1 / 8

A New Catalyst for Splitting Water into Molecular Oxygen - PowerPoint PPT Presentation


  • 90 Views
  • Uploaded on
  • Presentation posted in: General

A New Catalyst for Splitting Water into Molecular Oxygen. James M. Krier UC-Berkeley. Unique challenges ahead. Energy = N (GDP/N)(E/GDP).

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha

Download Presentation

A New Catalyst for Splitting Water into Molecular Oxygen

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


A New Catalyst for Splitting Water into Molecular Oxygen

James M. Krier

UC-Berkeley


Unique challenges ahead

Energy = N (GDP/N)(E/GDP)

Even with optimistic technological and conservation forecasts, the rapid economic growth in developing nations is predicted to double global energy needs by 2050

Per person GDP

Energy intensity

N. S. Lewis, D. G. Nocera, Proc. Natl. Acad. Sci. U.S.A. 103, 15729 (2006).


Power from the sun

2 H2(g) + O2(g) → 2 H2O(l)

∆H = -286 kJ/mol

  • Enough solar energy strikes the globe in one hour (4.3 x 1020 J) to power all human activity for one year (4.1 x 1020 J)

  • Photosynthesis by plants is an example of splitting water for energy storage

bcs.whfreeman.com/lehninger

N. S. Lewis, D. G. Nocera, Proc. Natl. Acad. Sci. U.S.A. 103, 15729 (2006).


The artificial plant

The oxygen reaction is tricky in both systems

N. S. Lewis, D. G. Nocera, Proc. Natl. Acad. Sci. U.S.A. 103, 15729 (2006).


Recent breakthrough

e-

e-

+

-

1.29 V

Conducting glass, such as indium tin oxide

0.5 mM Co(NO3)2

0.1 M KPi (potassium phosphate)

SEM image

Film is 2:1 as Co:Pi

Alternative:

Kanan, M. W. & Nocera, D. G. Science 321, 1072–1075 (2008).


Key features

  • Self-repair mechanism, in situ formation

    • Co2+, Co3+, Co4+ species likely responsible for balancing different oxidation steps

    • Co2+-HPO42- (aq)  Co3+-HPO42- (on electrode surface)

  • Composed of earth-abundant materials

  • Long lasting O2 production at low overpotential, neutral pH, room temperature/pressure

  • Drawbacks: large initial overpotential, not effective at high current

Kanan, M. W. & Nocera, D. G. Science 321, 1072–1075 (2008).


Your new house?

web.mit.edu/newsoffice/2008/oxygen-0731.html

Kanan, M. W. & Nocera, D. G. Science 321, 1072–1075 (2008).


Links to additional reading…

  • nature.com/nmat/journal/v7/n10/full/nmat2284.html

  • rsc.org/ej/CS/2009/b802262n.pdf

  • sciencemag.org/cgi/reprint/321/5892/1072.pdf

  • www.web.mit.edu/newsoffice/2008/oxygen-0731.html

  • www.pnas.org/content/103/43/15729.abstract


ad
  • Login