Contact with Electrically Conductive Inert Solids Alters Intrinsic Heterogeneous Brønsted Acid Catalysis.

Area of Science:

• Heterogeneous catalysis
• Surface chemistry
• Electrochemistry

Background:

• Interfacial electric fields at heterogeneous catalysts influence liquid-phase reaction kinetics.
• Electric fields are typically generated via potentiostats or redox-active species.
• Catalyst polarization is a known phenomenon affecting reaction rates.

Purpose of the Study:

• To investigate catalyst polarization induced by contact with inert solids.
• To demonstrate a novel method for controlling reaction rates through physical contact.
• To explore the implications of contact-induced polarization in heterogeneous catalysis.

Main Methods:

• Utilized dehydration of 1-methylcyclopentanol to 1-methylcyclopentene as a model reaction.
• Employed Brønsted-acidic carboxylic acid groups on carbon nanotubes as the catalyst.
• Investigated reaction rate changes upon contact with inert, thermally reduced carbon nanotubes.

Main Results:

• Catalyst contact with inert solids induced significant, order-of-magnitude changes in reaction rates.
• Contact-induced effects were observed under standard laboratory conditions with stirred catalyst powders.
• Particle-to-particle contact in suspensions reduced reaction rates approximately 8-fold.

Conclusions:

• Catalyst polarization can occur through simple contact with inert conductive solids, altering intrinsic reaction rates.
• This contact-induced polarization presents a new strategy for controlling liquid-phase reaction kinetics.
• The findings have broad implications for heterogeneous catalysis where catalyst particles interact with inert materials.