Highly distorted platinum nanorods for high-efficiency fuel cell catalysis

Abstract

Different from studies where less defective platinum (Pt)-based nanomaterials have been widely used to improve the catalysis of the oxygen reduction reaction (ORR) for proton-exchange membrane fuel cells (PEMFCs), herein we have demonstrated that a new class of Pt nanorods (NRs) with a highly distorted configuration can be applied as an advanced, high-efficiency fuel cell catalyst, as transformed from spongy Pt-tellurium NRs (PtTe2 NRs) through sequential chemical and electrochemical aging procedures. The resulting highly distorted Pt NRs exhibit excellent ORR-specific and mass activities of 4.70mA cm-2 and 2.77 A mg-1 Pt at 0.90 V versus the reversible hydrogen electrode (RHE), which are 18.8 and 16.3 times higher than those of commercial Pt/C catalyst, and the mass activity is 6.3 times higher than 2020 U.S. Department of Energy target. Additionally, negligible activity decays were observed after 30,000 cycles. The high ORR performance endows these unique Pt NRs with enhanced activity and lifetimes for practical fuel cell catalysis in comparison with commercial Pt/C, which is consistent with the experimental results. It has been demonstrated that the anomaly of strong electron-lattice coupling suppresses Coulombic repulsion for barrier-free electron transfer while concurrently exposing a large number of active sites, which is a key to superior high-performance fuel cell reactions.