Engineering CNT-supported PtRu nanoparticles with ultrathin carbon coating for optimized d-Band center and superior methanol oxidation performance

Abstract

Developing efficient and durable Pt-based catalysts for the methanol oxidation reaction (MOR) is crucial for direct methanol fuel cells (DMFCs), yet it remains a considerable challenge. This work demonstrates that using carbon nanotube (CNT) support combined with an ultrathin carbon coating can enhance the activity and durability of PtRu alloyed nanoparticles (NPs) for the MOR. The developed CNT-supported PtRu NPs with ultrathin carbon coating (CN@PtRu/CNTs) show significantly enhanced MOR activity and stability, primarily arising from their unique structural features, including CNT support, ultrathin carbon coating, and Ru alloying. The CNT support provides a high surface area and excellent conductivity, aiding efficient electron transfer. The ultrathin carbon coating stabilizes the PtRu NPs by preventing agglomeration and detachment and enhances electronic interactions, boosting catalytic performance. The Ru alloying modifies the electronic structure of Pt, improving catalytic properties and resistance to CO poisoning. The CN@PtRu/CNTs exhibit a MOR mass activity and stability significantly higher than commercial Pt/C. They also show great potential for practical DMFC applications, achieving higher power density and durability than Pt/C. DFT calculations indicate that the CNT support and CN coating improve the d-band center of Pt, facilitating key MOR steps, while Ru alloying enhances *OH adsorption, accelerating *CO oxidation.