Superprotonic Conduction Over Wide Humidity Range Driven by Enhanced Proton Dissociation

Area of Science:

• Materials Science
• Electrochemistry
• Chemical Engineering

Background:

• Proton conduction is crucial for energy applications, but is limited by proton dissociation.
• Research has focused on acidic groups, overlooking dissociation from intermediate species like H3O+.
• Intermediate species often have higher electron density, increasing proton binding and dissociation energy.

Purpose of the Study:

• To develop high-performance proton conductors by minimizing proton dissociation energy from intermediate species.
• To investigate a covalent organic framework (COF) for enhanced proton conduction.
• To understand the mechanisms reducing proton dissociation energy in COFs.

Main Methods:

• Construction of a covalent organic framework (COF) based proton conductor.
• Analysis of proton dissociation mechanisms within the COF.
• Evaluation of proton conduction performance over a wide humidity range.

Main Results:

• The developed COF exhibits superprotonic conduction across a broad humidity range.
• Proton dissociation energy from intermediates was significantly reduced.
• Crowded guest molecules mitigated excessive proton hydration.
• C-H···H+ interactions were established, weakening proton binding.

Conclusions:

• Diminishing intermediate proton dissociation energy is key for advanced proton conductors.
• The designed COF effectively enhances proton conduction through reduced electrostatic binding.
• This strategy offers a promising pathway for developing efficient proton conducting materials.