Stable NiPt–Mo2C active site pairs enable boosted water splitting and direct methanol fuel cell

Abstract

Sluggish kinetics of methanol oxidation reaction (MOR) and alkaline hydrogen evolution reaction (HER) even on precious Pt catalyst impede the large-scale commercialization of direct methanol fuel cell (DMFC) and water electrolysis technologies. Since both of MOR and alkaline HER are related to water dissociation reaction (WDR), it is reasonable to invite secondary active sites toward WDR to pair with Pt for boosted MOR and alkaline HER activity on Pt. Mo2C and Ni species are therefore employed to engineer NiPt–Mo2C active site pairs, which can be encapsulated in carbon cages, via an in-situ self-confinement strategy. Mass activity of Pt in NiPt–Mo2C@C toward HER is boosted to 11.3 A mgpt−1, 33 times higher than that of Pt/C. Similarly, MOR catalytic activity of Pt in NiPt–Mo2C@C is also improved by 10.5 times and the DMFC maximum power density is hence improved by 9-fold. By considering the great stability, NiPt–Mo2C@C exhibits great practical application potential in DMFCs and water electrolysers.

Keywords

• Hydrogen evolution reaction
• Methanol oxidation reaction
• Direct methanol fuel cell
• Active site pair
• Self-confinement