Wells, P. P; Qian, Y; King, C. R; Wiltshire, R. J. K.; Crabb, E. M.; Smart, L. E.; Thompsett, D and Russell, A. E.
To alloy or not to alloy? Cr modified Pt/C catalysts for PEM fuel cells.
Faraday Discussions, 138
The cathode electrocatalysts for proton exchange membrane (PEM) fuel cells are commonly platinum and platinum based alloy nanoparticles dispersed on a carbon support. Control over the particle size and composition has, historically, been attained empirically, making systematic studies of the effects of various structural parameters difficult. The controlled surface modification methodology used in this work has enabled the controlled modification of carbon supported Pt nanoparticles by Cr so as to yield nanoalloy particles with defined compositions. Subsequent heat treatment in 5% H-2 in N-2 resulted in the formation of a distinct Pt3Cr alloy phase which was either restricted to the surface of the particles or present throughout the bulk of the particle structure. Measurement of the oxygen reduction activity of the catalysts was accomplished using the rotating thin film electrode method and the activities obtained were related to the structure of the nanoalloy catalyst particles, largely determined using Cr K edge and Pt L-3 edge XAS.
||2008 Royal Society of Chemistry
||cathode electrocatalysts; proton exchange membrane (PEM) fuel cells; particle size; controlled surface modification methodology;
||Science > Life, Health and Chemical Sciences
||14 Oct 2009 09:43
||02 Dec 2010 20:39
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