Platinum Monolayer Electrocatalysts: Further improvements using novel high stability, low cost supporting cores
Radoslav R. Adzic
Chemistry Department, Brookhaven National Laboratory, Upton, NY 11973, U.S.A.
Although considerable advances in developing fuel cell catalysts were made over the last fifteen years, the amount of platinum used in electrocatalysts for the oxygen-reduction reaction (ORR) at fuel-cell cathodes remains a challange because of its insufficient catalytic activity and stability. Pt monolayer electrocatalysts offer several uniquely attractive properties to meet that challenge, including an ultra-low Pt content, the 100% Pt utilization and very high activity. Further improving of these electrocatalysts can be achieved by using novel high stability, low cost cores such as: i) Nitride containing non–noble metal, or non-noble metal alloy cores, ii) Au- stabilized non-noble metal alloy cores, iii) Ordered intermetallic compounds iv) Refractory metals codeposited Ni alloys and v) Graphene as support.
Distinct classes of the ORR core-shell electrocatalysts result from these modifications of cores.
Significantly enhanced the ORR activity as well as the durability of these catalysts is a consequence of combined geometrical, electronic and segregation effects on the Pt shells. The roles of each component in the catalyst was investigated and in the best case the catalyst showed a Pt group metal mass activity that was approximately 3 times higher than that of the commercial Pt/C electrocatalyst.
We recenly demonstrated extraordinary effects of strained Pt monolayer on Au on the kinetics of methanol and ethanaol oxidation. Details of these findings will be discussed at the conference.