(Invited) Alloy of Platinum with Rare Earth Metals for High Oxygen Reduction Reaction Activity and Durability

In the search for highly active and durable electrocatalysts for the oxygen reduction reaction (ORR), alloys of Pt with rare-earth metals (REM) have been demonstrated as one of the most promising candidates. However, their synthesis by conventional chemical methods is challenging, since REM have very low reduction potentials and high oxygen affinity leading to the formation of oxides rather than alloys. We prepared a series of carbon supported Pt-REM nanomaterials with a solid-state method[1], characterized by physico-chemical techniques and evaluated towards the ORR in acidic medium. The influence of the type of rare earth metal, of the Pt:REM ratio[2], of the post-synthesis treatment[3], and of the nature of the carbon support on the structural, morphological and electrochemical properties of the prepared electrocatalysts was investigated. In this presentation we will give an overview of the results obtained on these highly active and durable carbon-supported Pt-REM nanostructured electrocatalysts and of the challenges to be tackled for their application at the cathode of proton exchange membrane fuel cells. [1] Y. Hu, J.O. Jensen, L.N. Cleemann, B.A. Brandes, Q. Li, Synthesis of Pt–Rare Earth Metal Nanoalloys, J. Am. Chem. Soc. 142 (2020) 953–961. [2] C.A. Campos-Roldán, F. Pailloux, P.-Y. Blanchard, D.J. Jones, J. Rozière, S. Cavaliere, Rational Design of Carbon-Supported Platinum–Gadolinium Nanoalloys for Oxygen Reduction Reaction, ACS Catal. 11 (2021) 13519–13529. [3] C.A. Campos Roldán, F. Pailloux, P.-Y. Blanchard, D.J. Jones, J. Rozière, S. Cavaliere, Enhancing the Activity and Stability of Carbon-Supported Platinum-Gadolinium Nanoalloys towards the Oxygen Reduction Reaction, Nanoscale Adv. (2021). doi:10.1039/D1NA00740H.