Oxygen reduction reaction increased tolerance and fuel cell performance of Pt and RuxSey onto oxide–carbon composites

Pt and RuxSey nanoparticles were selectively deposited onto oxide sites of oxide–carbon composite substrates using the photo-deposition process and compared to conventional carbon support materials. The oxide was essentially anatase phase. Cyclic voltammetry and rotating disk electrode measurements for the oxygen reduction reaction (ORR) in formic acid containing-electrolyte showed a tolerance improvement for ORR of Pt supported on composite substrates. This positive substrate effect on platinum, turned out not to be favorable for RuxSey catalyst centers. On the other hand, the methanol tolerance for ORR was increased for both nanostructured materials supported on the oxide–carbon composite. Single H2/O2 fuel cell results were in agreement with half-cell electrochemical measurements on Pt, showing an improvement of the power density when using the oxide–carbon as substrate for the cathode. The composites were evaluated as cathode catalysts of an HCOOH laminar-flow fuel cell (LFFC) in which commercial Pd/C was used as an anode catalyst. The cathodes with RuxSey and Pt supported on TiO2/C improved the specific power density by 15% and 24%, respectively, with respect to carbon as support.