Enhancing Adsorption Desulfurization Performance Using Enriched Cu(I) Sites over Microenvironment-Modulated HKUST-1

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Adsorptive desulfurization of liquid hydrocarbon fuels is crucial for environmental protection.
• Metal-organic frameworks (MOFs) show promise for desulfurization but often suffer from inert metal sites.
• Modulating the MOF microenvironment is key to enhancing adsorption efficiency.

Purpose of the Study:

• To develop a novel method for enhancing the desulfurization performance of MOFs.
• To create abundant high-efficiency Cu(I) and Cu-coordination-unsaturated sites within MOFs.
• To improve pore structures around adsorptive sites for better sulfur compound capture.

Main Methods:

• Utilized Cerium(III) as a molecular tool to modulate the coordination microenvironment of HKUST-1 (a type of MOF).
• Fabricated enhanced MOF structures (CH-250) with improved Cu(I) and Cu-coordination-unsaturated sites.
• Investigated the adsorption capacities and affinities of the modified MOFs for aromatic sulfur compounds.

Main Results:

• The optimal CH-250 MOF demonstrated superior adsorptive capacities for thiophene (20.2 mg S g⁻¹), benzo-thiophene (28.0 mg S g⁻¹), and dibenzothiophene (58.3 mg S g⁻¹).
• The engineered Cu(I) sites exhibited stronger adsorption affinity for dibenzothiophene compared to the original Cu(II) sites.
• Significantly enhanced in-plane adsorption interactions were observed for dibenzothiophene on the modified MOF.

Conclusions:

• Ce-enhanced modulation is an effective strategy for fabricating high-performance MOFs for adsorption desulfurization.
• The engineered MOFs significantly outperform existing materials like zeolites and nanoporous carbons.
• Molecular engineering of MOF coordination microenvironments holds great potential for deep desulfurization applications.