Lewis Acid Sites Assisted PtCu/CeO₂-C Enabling High-Performance for Oxygen Reduction

Improvement in the durable and active low-Pt nanocatalysts for oxygen reduction reaction (ORR) is the essential target for clean energy. Herein, an efficient CeO₂ supported PtCu alloy catalyst (PtCu/CeO₂-C) for ORR in acid media is developed. The CeO₂ support can effectively anchor the PtCu particles and inhibit their migration during the long-life cycling, which is beneficial to the catalytic performance. According to the electrochemical experiments, the specific and mass activities of PtCu/CeO₂-C are 1.09 mA cm^-2 and 0.49 A mg_Pt ^-1 at 0.9 V, which are 9.9 and 6.1 times as large as that of Pt/C, demonstrating its outstanding ORR activities in acid media. Moreover, the theoretical studies confirm that oxygen vacancies (V_O) as Lewis acid sites can facilitate the adsorption and dissociation of O₂, regulate the electronic structure of Pt, and thus endow PtCu/CeO₂-C with an efficient 4-electron ORR pathway. The results suggest that the rational design of supported Pt-based catalysts is of great significance for efficient ORR reaction.