Anhydrous proton conducting materials based on sulfonated dimethylphenethylchlorosilane grafted mesoporous...

Area of Science:

• Materials Science
• Electrochemistry
• Chemical Engineering

Background:

• Fuel cell technology requires efficient proton conductivity at high temperatures and low humidity.
• Current proton exchange membranes face limitations under these demanding conditions, hindering commercialization.

Purpose of the Study:

• To investigate novel proton conducting materials based on functionalized mesoporous silica for fuel cell applications.
• To evaluate the performance of these materials under anhydrous conditions at elevated temperatures.

Main Methods:

• Synthesis of mesoporous silica functionalized with sulfonated dimethylphenethylchlorosilane.
• Characterization of material structure and properties using XRD, TEM, FT-IR, and solid-state NMR.
• Measurement of ionic conductivity and thermal stability (TGA) after ionic liquid impregnation.

Main Results:

• Covalent bonding of organic moieties to silica substrate confirmed.
• Grafted organic molecule density of 2.45 μmol m⁻² achieved.
• Composite materials demonstrated thermal stability up to 300 °C.
• Peak ionic conductivity of 1.14 × 10⁻² S cm⁻¹ at 160 °C under anhydrous conditions.
• Low activation energy for proton transport (9.24 kJ mol⁻¹).

Conclusions:

• The developed functionalized mesoporous silica composite shows promise as an efficient proton conductor for fuel cells operating at elevated temperatures and anhydrous conditions.
• This material addresses a critical bottleneck in fuel cell commercialization by enabling operation under challenging environments.
• The covalent functionalization strategy provides a stable and effective platform for proton conduction in advanced energy devices.