Ultra-stable Pt₅La intermetallic compound towards highly efficient oxygen reduction reaction

Designing feasible electrocatalysts towards oxygen reduction reaction (ORR) requires advancement in both activity and stability, where attaining high stability is of extreme importance as the catalysts are expected to work efficiently under frequent start-up/shut down circumstances for at least several thousand hours. Alloying platinum with early transition metals (i.e., Pt–La alloy) is revealed as efficient catalysts construction strategy to potentially satisfy these demands. Here we report a Pt₅La intermetallic compound synthesized by a novel and facile strategy. Due to the strong electronic interactions between Pt and La, the resultant Pt₅La alloy catalyst exhibits enhanced activity with half wave of 0.92 V and mass activity of 0.49 A·mg_Pt⁻¹, which strictly follows the 4e transfer pathway. More importantly, the catalyst performs superior stability during 30,000 cycles of accelerated stressed test (AST) with mass activity retention of 93.9%. This study provides new opportunities for future applications of Pt-rare earth metal alloy with excellent electrocatalytic properties.