Supported sub-5nm Pt–Fe intermetallic compounds for electrocatalytic application

Abstract

Supported chemically ordered Pt–Fe intermetallic compounds have been prepared through a straightforward two-stage approach. By taking advantage of this straightforward two-stage synthesis, we have for the first time successfully obtained supported Pt₃Fe₁ and Pt₁Fe₁ intermetallic nanoparticles with a mean size of less than 5 nm, a narrow size distribution and good dispersion. The nanoparticles of supported intermetallic Pt₃Fe₁ and Pt₁Fe₁ compounds showed superior electrocatalytic activities towards the oxygen reduction reaction (ORR). The ORR enhancement in supported electrocatalysts made from Pt–Fe intermetallic compounds may be attributed to their geometric and electronic structure. Accelerated durability tests (ADT) show that Pt₃Fe₁/C has better durability, the electrochemical surface area (ECSA) values of commercial Pt/C decreased by 49% after 5000 cycles, but Pt₁Fe₁/C showed a reduction in the ECSA value of 3% after 5000 cycles.