Nitrogen-rich Graphdiyne Film for Efficiently Suppressing the Methanol Crossover in Direct Methanol Fuel Cells

The inhibition of the methanol crossover is one of the intractable challenges in the direct methanol fuel cell. The graphdiyne(GDY) with atomic-level pores shows great potential in realizing the zero-permeation of methanol molecules. In this paper, an ultrathin layer of nitrogen-rich GDY film with a high nitrogen content is largely prepared and readily used for retarding the methanol permeation in the state-of-the-art commercial Nafion membrane. The high N-content in this porous GDY nanofilm remarkably increases the selective suppression in methanol transfer, and single-layer GDY film can efficiently prevent 43% methanol crossover and the value of the double-layer GDY film can be high up to 69%. The power performance and the long-term stability of the cell are obviously improved due to the reduced methanol crossover.