Atomically ordered Pt3Mn intermetallic electrocatalysts for the oxygen reduction reaction in fuel cells

Abstract

Here, we introduce structurally ordered platinum–manganese nanoparticles on a carbon support (Pt₃Mn intermetallic/C) as a highly efficient and durable catalyst for the oxygen reduction reaction (ORR). Using a facile method, Pt₃Mn intermetallic nanoparticles were obtained without severe agglomeration. Compared to commercial Pt/C, Pt₃Mn intermetallic/C demonstrates superior initial ORR activity and stability. DFT calculations demonstrated highly active and stable Pt₃Mn by calculations of the oxygen adsorption energy, segregation energy, and Pt dissolution potential. One of the main challenges in the commercialization of new ORR catalysts is the successful transition from a rotating disk electrode to a single cell. At a cell voltage of 0.7 V, Pt₃Mn intermetallic/C (550 → 486 mA cm⁻², −11.63%) showed excellent initial cell performance and stability after 10k voltage cycles compared to Pt/C (419 → 308 mA cm⁻², −26.49%). We report for the first time a Pt₃Mn intermetallic ORR catalyst that achieves single-cell performance superior to that of Pt/C.