Combinatorial Studies of Pt-based Oxygen Reductionelectrocatalysts: Synthesis, Stability, and Activity

Completed in 2007, this work is a PhD thesis thatpresents measurements of the stability and activitiesof Pt-based oxygen reduction reactionelectrocatalysts for proton exchange membrane fuelcells using a combinatorial materials synthesisapproach developed at Dalhousie University. Numerouscombinatorial libraries of Pt1-xMx (M = Fe, Ni, Mn)and Pt1-x-yMxMy' (M, M' = Co, Ni, Mn, Fe) wereprepared by magnetron sputtering using 3M'sproprietary nano-structured thin film supports assubstrates. The composition of these libraries afteracid treatment was very close to the electrocatalyststested in hydrogen fuel cells, thus showing that acidtreatment can effectively mimic the fuel cellenvironment. Detailed studies of the ORR activity ofsputtered Pt1-xCox films, using rotating ring-diskelectrode (RRDE) techniques, importance of bench linemeasurements and the impact of catalyst loadings inRRDE measurements are also discussed.