PdNi/N-C dodecahedra with surface-enriched Pd for efficient methanol electro-oxidation in alkaline media.

The methanol electrooxidation reaction (MOR) is a key anodic process in direct methanol fuel cells, yet its practical application remains hindered by several critical challenges, including the high cost and limited reserves of noble metal catalysts, severe CO poisoning of active sites, and insufficient long-term durability. Herein we report a PdNi/N-C catalyst derived from ZIF-8 dodecahedra, featuring Pd-enriched surfaces on a nitrogen-doped carbon support. The unique architecture ensures high Pd utilization while the PdNi alloying effect, combined with the presence of excess Ni nanoparticles, promotes the bifunctional mechanism to effectively mitigate CO poisoning and enhance reaction kinetics. The catalyst delivers a mass activity of 6.20 A mg-1Pd for the MOR, which is 6.75 times higher than that of commercial Pd/C, along with significantly improved stability during accelerated durability tests. This work highlights the importance of support morphology and Pd surface enrichment in bimetallic catalyst design, offering a promising strategy for developing high-performance and cost-effective anode catalysts for direct methanol fuel cells.