Constructing multiple active sites in iron oxide catalysts for improving carbonylation reactions

Area of Science:

• Materials Science
• Catalysis
• Surface Chemistry

Background:

• Surface engineering is crucial for enhancing heterogeneous catalyst performance.
• Understanding the role of surface imperfections, like oxygen vacancies, on catalytic active sites is underexplored.
• Iron(III) oxide (Fe2O3) is a common catalyst, but its surface defect sites require further investigation.

Purpose of the Study:

• To investigate the catalytic behavior of different iron (Fe) sites around oxygen vacancies in Fe2O3.
• To demonstrate the efficacy of oxygen vacancy-induced Fe2O3 for carbonylation reactions.
• To develop a recyclable catalytic system for synthesizing carbonylated compounds.

Main Methods:

• Synthesis of oxygen vacancy-induced Fe2O3 catalyst.
• Characterization techniques to confirm oxygen vacancy formation.
• Catalytic testing for carbonylation of aryl halides with amines/alcohols using carbon monoxide (CO).
• Density functional theory (DFT) calculations and control experiments.

Main Results:

• Fe2O3 with oxygen vacancies exhibited significant catalytic performance in carbonylation reactions.
• The system showed excellent activity, selectivity, and reusability for synthesizing carbonylated chemicals.
• DFT calculations and control experiments confirmed the vital role of specific Fe sites around oxygen vacancies in catalyzing reaction steps.

Conclusions:

• Oxygen vacancies in Fe2O3 create distinct Fe active sites that enhance catalytic activity.
• The developed catalyst is effective for aminocarbonylation and alkoxycarbonylation, producing valuable molecules.
• This study highlights the potential of combinatorial sites catalysis for multistep reactions.