Fine-grained and fully ordered intermetallic PtFe catalysts with largely enhanced catalytic activity and durability

Catalytic activity and durability improvements are still the main challenges in fuel cell commercialization. To enhance nanocatalyst performance and durability for oxygen reduction reaction (ORR), we prepare 3.6 nm sized PtFe particles with a fully ordered intermetallic structure and entrap them in a porous carbon (PtFe@C). This nanocatalyst toward ORR exhibits 8-10 times enhancement in specific and mass activities over the commercial catalyst of Pt/C. Such a large enhancement is the highest, when compared with all other kinds of intermetallic catalysts reported in the literature. Accelerated durability testing has induced only a small change to the ordered structure and a minor loss of the activity after thousands of potential cycles under harsh electrochemical conditions. The high activity and durability are attributed to the fine-grained and ordered structure of the nanoparticle and the confining effect provided by the porous carbon. The nanoparticle, PtFe@C, represents a new strategy for performance optimization and cost reduction and promoting practical applications of fuel cells. Structurally ordered intermetallic particles encapsulated in carbon layers exhibit excellent catalytic activity and durability toward oxygen reduction reaction.