Electrocatalysis in confined spaces: interplay between well-defined materials and the microenvironment

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Confined catalysis offers tunable active sites and microenvironments for efficient chemical conversions.
• Electrochemical reactions benefit from confined spaces, which modulate electronic, geometric, and mechanical effects.
• Stabilizing charge-transfer intermediates and enhancing reaction kinetics are key advantages of confined electrocatalysis.

Purpose of the Study:

• To review fundamental concepts of confined catalysis using DFT calculations and experimental data.
• To present the design and applications of space-confined electrocatalysts, focusing on carbon-based materials.
• To highlight metal-based materials confined in carbon nanotubes (CNTs) for emerging electrochemical reactions.

Main Methods:

• Summary of density functional theory (DFT) calculations.
• Review of experimental investigations on confined catalysis.
• Focus on rational design principles for space-confined electrocatalysts.

Main Results:

• Carbon-based materials, especially CNTs, provide effective confined environments for electrocatalysts.
• Metal-based materials confined in CNTs show promise for oxygen reduction reaction (ORR).
• Applications extend to water-splitting, carbon dioxide reduction reaction (CO2RR), and nitrogen reduction reaction (NRR).

Conclusions:

• Confined electrocatalysis, particularly using CNT-confined metal catalysts, offers significant potential for various electrochemical reactions.
• Further research is needed to address challenges and explore future directions in space-confined electrocatalysis.