Efficient Methane Purification Using a Robust and Recoverable Hydrogen-Bonded Organic Framework.

Area of Science:

• Materials Science
• Chemical Engineering
• Separation Science

Background:

• Efficient methane separation is crucial for its use as clean energy and chemical feedstock.
• Developing solid adsorbents with structural integrity, high capacity, and easy recovery for methane purification remains a significant challenge.

Purpose of the Study:

• To report a novel ultramicroporous hydrogen-bonded organic framework (HOF) for methane purification.
• To investigate the material's stability, selectivity, and performance in separating methane from mixed gases.

Main Methods:

• Synthesis of an ultramicroporous HOF using a tetracyano bithiophene-functionalized ligand.
• Evaluation of chemical stability across a wide pH range.
• Assessment of selective adsorption of acetylene and carbon dioxide over methane.
• Dynamic breakthrough experiments for methane purification from binary and ternary gas mixtures.

Main Results:

• The HOF exhibits exceptional chemical stability in strong acidic and basic solutions.
• It demonstrates the highest reported packing densities and adsorption selectivities for acetylene and carbon dioxide among HOFs.
• Dynamic breakthrough experiments confirmed highly efficient methane purification with productivities up to 2.34 mol·kg⁻¹.
• The material requires moderate regeneration energy and can be easily regenerated.

Conclusions:

• The developed HOF is a promising single solid adsorbent for efficient methane purification.
• Its robust structure, high selectivity, and facile regeneration address key challenges in methane depuration.
• This material facilitates methane's application as a clean energy source and chemical raw material.