Proton selective anode nanochannel for efficient methanol utilization

Abstract

A large area of freestanding graphdiyne films with an independent anode array of GDY@PtCu was prepared. Structural analysis confirmed that electroactive Pt4.4Cu alloy nanoparticles with a diameter size of 4.2 nm, which can be anchored on the inner wall of the GDY nanochannel. This highly active anodic electrode demonstrates intrinsic selectivity and efficient suppression of methanol crossover and achieves selective proton transport in the electrode, due to GDY special surface and super-large pore structure. Our results show that, in this process, the methanol diffusion pathway is highly ordered, methanol electrooxidation is effectively confined in ordered GDY nanochannels. As-prepared GDY@PtCu anode not only demonstrated superior electrocatalytic activity and duration, at the same time, the utilization efficiency of catalyst and methanol fuel is greatly improved. A DMFC using such an anodic electrode material exhibits superior power density of 90 mW cm-2 at 80 °C with an ultralow Pt loading (0.8 mg cm-2) and the methanol crossover is greatly suppressed up to 33%. After a 500 h long-term testing, the DMFC based-on freestanding GDY@PtCu anode still maintains high retention (81%) of its original power density.