Catalytic oxidative desulfurisation over Co/Fe-γAl₂O₃ catalyst: performance, characterisation and computational study

Area of Science:

• Catalysis Science and Technology
• Petroleum Refining and Fuel Science
• Materials Science for Energy Applications

Background:

• Global demand for ultra-low sulfur diesel necessitates cost-effective production technologies.
• Traditional desulfurization methods often require harsh conditions or expensive catalysts.
• Nanoparticle catalysts offer potential for enhanced activity and efficiency in chemical processes.

Purpose of the Study:

• To develop a low-cost nanoparticle catalyst for efficient diesel desulfurization.
• To investigate the effect of cobalt modification on iron-aluminum oxide catalysts.
• To optimize catalyst composition and calcination temperature for maximum sulfur removal.

Main Methods:

• Synthesis of Fe/Al₂O₃ catalyst modified with cobalt oxide (10-30 wt%) via wet impregnation.
• Catalyst characterization to confirm the formation of Co₃O₄ and Fe₃O₄ species.
• Evaluation of desulfurization activity using thiophene, dibenzothiophene (DBT), and 4,6-dimethyl dibenzothiophene (4,6-DMDBT) as model sulfur compounds.
• Density Functional Theory (DFT) calculations to elucidate reaction pathways for DBT oxidation.

Main Results:

• Cobalt modification significantly enhanced the performance of the Fe/Al₂O₃ catalyst.
• The optimized Co/Fe-Al₂O₃ catalyst (10:90 dopant ratio, calcined at 400 °C) achieved high desulfurization rates: 96% for thiophene, 100% for DBT, and 92% for 4,6-DMDBT.
• DFT analysis identified two pathways for complete DBT oxidation with an overall energy of -40.78 eV.

Conclusions:

• Cobalt-modified iron-aluminum oxide nanoparticles represent a highly effective catalyst for deep desulfurization.
• The developed catalyst operates efficiently under mild conditions, aligning with low-cost technology requirements.
• This research provides a promising pathway for producing ultra-low sulfur diesel fuel.