Highly Stable Amide-Functionalized Zirconium-Organic Frameworks: Synthesis, Structure, and Methane Storage Capacity

Area of Science:

• Materials Science
• Chemistry
• Chemical Engineering

Background:

• Metal-organic frameworks (MOFs) are promising for methane storage but often suffer from stability issues.
• Zirconium-based MOFs offer enhanced stability, while amide groups can improve gas adsorption.
• Developing robust MOFs with high methane storage capacity is crucial for energy applications.

Purpose of the Study:

• To design and synthesize novel UiO-66 type zirconium-based MOFs (Zr-fcu) with varying functional groups.
• To evaluate the stability and methane storage performance of these new MOF materials.
• To establish a structure-property relationship for functionalized Zr-fcu MOFs in methane storage.

Main Methods:

• Synthesis of Zr-fcu MOFs using amide-functionalized dicarboxylate ligands and ZrCl4.
• Characterization using single-crystal X-ray diffraction and N2 sorption isotherms.
• Assessment of acid-base stability and volumetric methane storage capacity at different temperatures and pressures.

Main Results:

• Successfully synthesized four Zr-fcu MOFs (Zr-fcu-H/F/CH3/OH) with archetypal fcu topology.
• Materials exhibited high surface areas, pore volumes, and excellent hydrolytic stability across a wide pH range (3-11).
• Achieved significant volumetric methane storage capacities, with Zr-fcu-H reaching 187/217 cm³(STP)/cm³ at 298/273 K and 80 bar.

Conclusions:

• The synthesized Zr-fcu MOFs demonstrate superior hydrolytic stability and high methane storage working capacities.
• Functionalization of ligands with different side groups influences methane storage performance.
• These zirconium-based crystalline porous materials represent a promising advancement for efficient methane storage solutions.