Pt Ternary Alloy with Rare Earth Metal - Pt₅Ce-Co Intermetallic Nanoparticles as Highly Active Catalyst for Oxygen Reduction Reaction in PEMFCs

Alloying with rare earth elements is an important direction of exploring in Pt-based alloy design in oxygen reduction reaction (ORR), due to its special electronic configurations. Here we reported a ternary intermetallic alloy Pt 5 Ce-Co/C. The electronic valence state of Pt alloys was modified by the unique 4f orbital and the contraction effect of Ce, plus the additional active sites provided by the Co incorporation, optimizing the adsorption energy of the reaction intermediates, and effectively improving the electrocatalytic performance. The Pt 5 Ce-Co/C achieved 2.8 A∙mg Pt -1 of mass activity in ORR catalysis, which can maintain 1.4 A∙mg Pt -1 after 30k of accelerated stress test (AST). For membrane electrode assembly test, Pt 5 Ce-Co/C shows an initial mass activity of 724 mA∙mg Pt -1 , and a current density of 1876 mA∙cm -2 at 0.7 V under heavy-duty vehicle testing. This work provides an avenue to design advanced PGM ternary alloys by incorporating rare-earth metals to promote the catalyst performance.