Functionalized carbon nanofibers as solid-acid catalysts for transesterification

Area of Science:

• Materials Science
• Catalysis
• Green Chemistry

Background:

• Developing efficient and stable catalysts is crucial for sustainable chemical processes.
• Sulfonated carbons are widely used heterogeneous acid catalysts.
• Accessibility of acid sites to substrates can significantly impact catalytic performance.

Purpose of the Study:

• To synthesize novel acidic carbon materials using functionalized carbon nanofibers (CNFs).
• To evaluate the catalytic performance of these CNFs in the transesterification of triolein and methanol.
• To compare the efficacy of functionalized CNFs with conventional sulfonated carbons.

Main Methods:

• In situ diazonium coupling was employed to functionalize carbon nanofibers with aryl sulfonic acid groups.
• The functionalized CNFs were characterized for their acidic properties and accessibility of functional groups.
• Catalytic activity and stability were assessed for the transesterification reaction using triolein and methanol.

Main Results:

• Aryl sulfonic acid-functionalized CNFs were successfully synthesized, creating an acidic carbon material.
• The functionalized CNFs demonstrated high efficiency in catalyzing the transesterification of triolein and methanol.
• These CNFs exhibited superior stability and higher activity per acid site compared to conventional sulfonated carbons.
• A linear correlation was observed between the degree of functionalization (sulfonic acid sites) and catalytic performance.

Conclusions:

• In situ diazonium coupling is an effective method for creating highly accessible acidic sites on CNFs.
• Functionalized CNFs serve as efficient and stable heterogeneous catalysts for transesterification reactions.
• The catalytic performance is directly tunable by controlling the density of sulfonic acid groups on the CNFs.