Photocatalytically Generated Pt∕C–TiO[sub 2] Electrocatalysts with Enhanced Catalyst Dispersion for Improved Membrane Durability in Polymer Electrolyte Fuel Cells

Abstract

Platinum/carbon/titanium oxide electrocatalysts were prepared by a heterogeneous photocatalysis method wherein the semiconductor optoelectronic properties of were exploited to facilitate photoreduction of a platinum precursor on the surface of the composite whole yielding excellent platinum dispersion. The loading in the electrocatalyst was varied in the ranges: and the Pt content was varied from . The physical and electrochemical characteristics of these new-generation electrocatalysts were benchmarked against commercial samples. Membrane electrode assemblies were prepared using these composite electrocatalysts and tested with hydrogen as fuel and oxygen/air as oxidants. The fluoride emission rate (in units of ) was estimated by condensate water analyses and found to be reduced by approximately an order of magnitude upon addition of . Implicatiońs of these data for optimization of polymer electrolyte fuel cells in terms of durability and performance are presented.