Aqueous proton-selective conduction across two-dimensional graphyne.

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Direct methanol fuel cells offer advantages but face challenges with methanol crossover.
• Proton-selective membranes are crucial for efficient fuel cell operation.

Purpose of the Study:

• To investigate the proton-selective conduction properties of 2D graphyne in aqueous environments.
• To evaluate the potential of 2D graphyne as a zero-methanol crossover membrane.

Main Methods:

• Computational simulations were used to study proton and methanol transport through 2D graphyne.
• The effect of pore size on conduction mechanisms and methanol blocking was analyzed.

Main Results:

• Proton conduction mechanisms in graphyne pores transition with increasing pore size.
• A patterned aqueous/vacuum interphase facilitates Grotthuss proton transport at larger pore sizes.
• 2D graphyne with pore sizes below 1.45 nm effectively blocks methanol crossover.

Conclusions:

• 2D graphyne exhibits tunable proton selectivity and excellent methanol blocking capabilities.
• Graphyne-based membranes with optimized pore sizes are promising for developing high-performance, zero-crossover direct methanol fuel cells.