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Abstract: Through decorating commercial Pt/C catalyst with a binary oxide of silicon and tin, a catalyst with significantly enhanced self-humidification capacity and ultra-high stability has been successfully prepared. After 5000 cycles, ECSA and ORR activity decay by only 30% and 28.4%, respectively, for our optimal decorated catalyst, compared with 75% and 99.9% for undecorated Pt/C under the same conditions. We attribute this improvement to the prevention of Pt nanoparticle aggregation and the synergistic effects between the Pt active component and the binary oxide. The decorated catalyst also exhibits excellent self-humidification. Under non-humidified operating conditions, a membrane electrode assembly (MEA) with a decorated Pt/C catalyst anode is discharged at 0.6 V for 8 h with only slight current density decay, whereas serious decay is observed for an MEA with a non-decorated Pt/C anode. The catalysts are characterized using XRD, SEM/TEM, XPS, and contacted angle measurement. We find that the dissolution, migration, and aggregation of Pt nanoparticles can be effectively prevented by decoration with the binary oxide, and that the contact angle is decreased by 56°, indicating great improvement in the catalyst’s wettability. The interactions between Pt and oxide, Sn and Si are revealed by XPS analysis. This work may provide a facile and effective way to address the durability and humidification issues of PEM fuel cells.Graphical Abstract: An oxide modified Pt/C catalyst was prepared by decorating the commercial Tanaka Pt/C catalyst with a binary oxide of Sn and Si, the catalyst exhibited significantly enhanced stability/durability, slightly enhanced activity and excellent self-humidification property. The catalysts were characterized with HRTEM, XPS etc. The enhancements should be attributed to the prevention of the coated binary oxide to the aggregation of Pt, the corrosion of carbon support. And self-humidification may be resulted from the wettability of the silicon oxide. [ABSTRACT FROM AUTHOR]

Core-shell structured catalysts, made by placing either a monolayer or a thin layer of a noble metal on relatively cheap core-metal nanoparticles, are fascinating and promising fuel cell catalysts due to their high utilization of noble metals. Here, we report our development of a core-shell structured catalyst, Ru@Pt/C, generated by a novel and facile pulse electrochemical deposition (PED) approach. We demonstrate that compared with a commercial Pt/C catalyst, this novel catalyst achieves over four times higher mass activity towards the anodic oxidation of methanol, and 3.6 times higher mass activity towards the cathodic reduction of oxygen. Importantly, we find that the intrinsic activity of Pt in this Ru@Pt/C catalyst is doubled due to the formation of the core-shell structure. The catalyst also shows superior stability: even after 2000 scans, it still retains up to 90% of the peak current. Our findings demonstrate that this novel PED approach is a promising method for preparing high-performance core-shell catalysts for fuel cell applications. [ABSTRACT FROM AUTHOR]