Ferromagnetic L1<sub>2</sub>‐Pt<sub>3</sub>Co Nanowires with Spin‐Polarized Orbitals for Fast and Selective Oxygen Reduction Electrocatalysis
Yikun Su, Zhaoyang Wang, Ruoxi Gao, Qifan Wu, Jinlai Zhao, Guangming Zhu, Qiliang Li, Hongbin Xu, Yiye Pan, Kunming Gu, Chiara Biz, Mauro Fianchini, José Gracia
Abstract
Abstract Magnetic alloys are key to develop efficient catalysts for oxygen reduction reaction (ORR) in fuel cells. During the last decade, it has been shown that spin manipulation of magnetic materials can improve the kinetics of triplet state 3 O 2 electrocatalysis, promoting the unification between the physics of strongly correlated materials and heterogeneous catalysis. In this study, structurally ordered Pt 3 Co nanowires (NWs) are synthesized, and their ORR catalytic performances are studied in detail. These intermetallic ordered L1 2 ‐Pt 3 Co NWs exhibit stronger ferromagnetism, superior ORR catalytic activity, and higher tolerance to carbon monoxide than related disordered A1‐Pt 3 Co NWs, and commercial Pt/C catalyst. These characteristics make them one of (if not) the best catalyst reported nowadays. Density functional theory calculations prove that the L1 2 ‐Pt 3 Co(111) surface displays a lower activation barrier at the ORR rate‐limiting step and better selectivity H 2 O 2 /H 2 O (i.e., lower production of H 2 O 2 ) compared with disordered A1‐Pt 3 Co(111). ORR reactivity increases with the level of Co order in the slab. Moreover, L1 2 ‐Pt 3 Co(111) displays more favorable thermodynamics, decreasing the adsorption enthalpies of 3 O 2 , and lower ORR rate‐limiting step, due to ferromagnetic quantum spin exchange interactions (QSEI), compared with Pt(111).