Mesoporous carbon is a form of porous carbon with pore sizes between 2 and 50 nanometers (nm), as defined by International Union of Pure and Applied Chemistry (IUPAC). Unlike conventional activated carbon, which is dominated by extremely small micropores (pore size < 2 nm), mesoporous carbon is engineered with well-controlled pores that have attracted significant interest for advanced energy technologies.
As a special carbon material, mesoporous carbon has found widespread use in advanced applications including lithium-ion batteries, fuel cells, and heterogeneous catalysis. Today, researchers and manufacturers can precisely tailor pore size, surface area, and particle morphology to optimize performance for specific applications.
What Is the Structure of Mesoporous Carbon?
Mesoporous carbon consists of amorphous carbon or closely packed planar graphene sheets containing a network of pores with diameters ranging from 2–50 nm.
These pores allow mesoporous carbon to disperse active materials such as catalyst nanoparticles within its large accessible internal surface area, increasing catalyst utilization and catalytic activity. Mesoporous carbon can exhibit high surface area exceeding 1000 m2/g, providing abundant active surface for adsorption and electrochemical reactions. Its larger pores reduce mass transport resistance compared with predominantly microporous activated carbon.
What Is Mesoporous Carbon Made From?
Mesoporous carbon can be produced from many carbon-rich precursors, such as pitch, sucrose, and phenolic resins.
The choice of precursor strongly influences the final material properties, such as pore size structure, surface chemistry, graphitization, and structural stability.
For example, mesophase pitch has been reported to generate non-microporous carbons, whereas sucrose is prone to create complementary micropores during carbonization.
What Are the Main Types of Mesoporous Carbon?
Mesoporous carbon can be classified in several different ways:
- Structural classification: ordered vs. disordered mesoporous carbon
- Template-based classification: soft template vs. hard template
- Morphological classification: nanospheres vs. nanofibers vs. scaffolds
Each category may offer unique advantages for different applications.
We believe ordered, well-controlled mesoporous carbon with interconnected pore networks and open end provides faster mass transport, improved utilization of active surface area, and superior electrochemical performance in many energy applications.
How Is Mesoporous Carbon Manufactured?
Several manufacturing methods are used depending on the desired pore structure and application.
Hard-Template Method
The hard-template process generally involves mixing an inorganic template with a carbon precursor. After carbonizing the precursor at high temperature, the template is then chemically removed to generate the porous carbon framework.
This approach offers exceptional control over pore size and structure than other methods.
Soft-Template Method
Soft-template synthesis generally consists of mixing a carbon precursor with a self-assembling surfactant. After allowing the structure to organize, carbonize the material. The template decomposes during high-temperature carbonization.
This method can produce highly ordered mesoporous carbon without requiring template removal by chemical etching.
Activation Processes
Mesoporous structures can also be developed through activation processes using steam, carbon dioxide, and KOH.
Activation enlarges existing pores and increases internal surface area, although pore size distribution is generally less uniform than template-based methods.
What Are the Main Applications of Mesoporous Carbon?
Mesoporous carbon is used across a wide range of advanced technologies.
Lithium-Ion Batteries
Mesoporous carbon serves as an ideal carbon framework for silicon-carbon anodes.
Its pore structure helps accommodate silicon volume expansion, improve electrical conductivity, and increase cycle life.
PEM Fuel Cells and Water Electrolyzers
Mesoporous carbon is widely used as a catalyst support for platinum and platinum-alloy catalysts in proton exchange membrane (PEM) fuel cells and electrolyzers.
Its high surface area and interconnected pores help disperse catalyst nanoparticles uniformly, improve catalyst utilization, and enhance mass transport of reactants. Further graphitized, mesophase pitch-derived mesoporous carbon exhibit superior carbon corrosion resistance, significantly extending the catalyst lifetime.
There are other applications for mesoporous carbon, including lithium-sulfur batteries, supercapacitors, drug delivery, and adsorption.