In situ shaped PtPd nanocubes on common carbon powder for efficient methanol electrooxidation in practical fuel cells

Abstract

Platinum-group-metal-based polyhedral nanostructures generally possess high catalytic activity for electrochemical reactions owing to their numerous edges, corners, and well-defined lattice planes. However, their direct synthesis on common carbon powder is difficult, which considerably hinders their applications in practical devices. Herein, we report PtPd nanocubes (NCs) grown in situ on commercial carbon powder (Vulcan XC-72R) using a facile one-pot method. The as-prepared PtPd NCs/C (∼20 wt% metal) possess Pt-enriched surfaces, enabling the mass activity (MA) of methanol oxidation reaction (MOR) up to 1.77 A mgPt−1, which is 3.34/3.69 times that of commercial PtRu/C and Pt/C, respectively. With an average size of 8–10 nm, the PtPd NCs/C exhibit high stability, retaining over 80% initial MA against MOR in an accelerated durability test. For practical direct-methanol fuel cell (DMFC) operation, the PtPd NC/C as an anode catalyst delivered a maximum power density of 0.232 W cm−2 with high-concentration methanol (10 M) flow, which is 1.6 times higher than that for commercial PtRu/C under the same conditions. Moreover, the PtPd NCs/C demonstrated excellent durability for DMFC operation with much lower voltage decay than commercial PtRu/C, indicating its excellent potential for practical DMFC applications. © 2023 Hydrogen Energy Publications LLC