Titanium Dioxide-Supported Platinum Catalyst Provides Ultrahigh Stability for PEM Fuel Cell Applications
27 September 2009
A team at the University of South Carolina synthesized a titanium dioxide (TiO2) and platinum catalyst supported on TiO2 (Pt/TiO2) for use in a fuel cell. The synthesized Pt/TiO2 electrocatalyst exhibits excellent fuel cell performance as well as ultrahigh stability—enabling much longer fuel cell life—at high positive potentials.
|Pt particles in the Membrane Electrode Assembly. (a) Non-corroding. (b) Corroded electrode showing (1) Agglomeration, (2) Coalescence, and (3) Loss of Pt Particles. Credit: ACS, Huang et al. Click to enlarge.|
A report on their work was published online 9 September in the Journal of the American Chemical Society.
A great deal of the current work on PEM fuel cells is focusing on improved fuel cell reliability and durability. Several factors can shorten fuel cell lifetime, including the dissolution and sintering of the platinum catalyst particles; corrosion of the carbon support for the catalyst; and membrane thinning.
Titanium dioxide is widely used in photocatalysis, photovoltaics, water splitting, and gas sensors; it possesses good mechanical resistance and stability in acidic and oxidative environments. However, its low electrical conductivity has prevented its use in fuel cells.
The University of South Carolina catalyst addresses the conductivity issue, while offering a solution to the stability issue posed by Pt/C catalysts. In addition to showing performance comparable to or better than a Pt/C catalyst, the Pt/TiO2 catalyst demonstrated much better stability over time, with little potential loss.
|(Left) Cell potential and power density of Pt/C catalyst and Pt/TiO2. (Right) Potential loss over time. Credit: ACS, Huang et al. Click to enlarge.|
The excellent fuel cell performance of the Pt/TiO2 electrocatalyst was attributed to the low mass transport limitation in the cathode catalyst layer. The AST results indicated an ultrahigh stability of the Pt/TiO2 electrocatalysts. The SMSI and corrosion resistance of the TiO2 support enhanced the stability of the Pt catalysts. On the basis of the experimental results reported above, this Pt/TiO2 electrocatalyst can be considered as an alternative cathode electrocatalyst to improve the reliability and durability of PEMFCs.—Huang et al.
Sheng-Yang Huang, Prabhu Ganesan, Sehkyu Park and Branko N. Popov (2009) Development of a Titanium Dioxide-Supported Platinum Catalyst with Ultrahigh Stability for Polymer Electrolyte Membrane Fuel Cell Applications. J. Am. Chem. Soc., Article ASAP doi: 10.1021/ja904810h
If I follow correctly, the right graph shows a huge improvement in corrosion resistance.
Posted by: kelly | 27 September 2009 at 11:04 AM
Either that or that flaming chipmunks are divebombing the pope.. Man they REALY need to make more readable graphs.
Posted by: wintermane2000 | 27 September 2009 at 04:50 PM
Nope, the improvement is so dramatic it is actually hard to read. The Pt/TiO2 catalyst shows essentially no corrosion over time. Very encouraging and very impressive work though I'd like to know the testing conditions (e.g. presence of sulfur, etc.)
Posted by: GreenPlease | 27 September 2009 at 06:23 PM