Metal Organic Frameworks (MOFs) have emerged as one of the most promising classes of porous materials for applications in gas storage, catalysis, environmental remediation, and energy systems. But behind every crystalline MOF structure lies a carefully designed synthesis process that determines the crystallinity, porosity and stability of the final material.

Here we explore how MOFs are synthesized from small-scale in laboratory to industrial scale.

1. The Basic Principles of MOF Synthesis

MOFs' formation is fundamentally a self-assembly process between Metal ions or clusters (acting as nodes) and Organic linkers (acting as bridges).

Under controlled conditions, when mixed they form extended coordination networks through metal–ligand coordination bonds, generating crystalline frameworks with nanoscale porosity.

The reaction conditions: temperature, solvent, concentration and pH. These conditions directly affect crystal size, morphology and purity.

2. Common Synthesis Methods

1) Solvothermal and Hydrothermal Synthesis

The most widely used method for producing MOFs involves dissolving metal salts and organic linkers in a solvent and heating the mixture in a sealed vessel (autoclave).

Advantages:

• High crystallinity
• Controlled nucleation and growth

Limitations:

• Long reaction time
• Solvent-intensive process

2) Microwave-assisted Synthesis

Microwave energy provides rapid and uniform heating, significantly shortening the synthesis time.

Advantages:

• Faster crystallization, minutes instead of hours
• Smaller and more uniform crystals

Applications:

Ideal for producing nanostructured MOFs and high-throughput screening of reaction conditions.

3) Mechanochemical (Solvent-Free) Synthesis

There is green chemistry approach that uses mechanical force (grinding, ball milling) to drive the reaction between metal salts and organic linkers without solvents.

Advantages:

• Environmentally friendly
• Scalable and cost-effective
• Avoids toxic solvents

Examples:

ZIF-8 and HKUST-1 can be successfully prepared by simple mechanochemical routes.

4) Electrochemical Synthesis

Metal ions are released directly from an electrode into the solution, reacting with ligands to form MOF films or powders.

Advantages:

• No external metal salts required
• Controlled crystal growth on electrode surface

Applications:

Used for MOF-coated electrodes, membranes, and sensor devices.

5) Continuous Flow and Industrial Synthesis

For large-scale production, continuous flow reactors and microreactor systems provide better control and reproducibility.

Features:

• Continuous feeding of reagents
• Rapid heat and mass transfer
• Scalable up to kilogram or ton level

Example:

BASF produce Basolite® with commercial processes by use continuous reactors efficiently.

3. Factors Influencing MOF Crystallization

4. Post-Synthesis Processing and Activation

After synthesis, MOFs typically undergo washing, solvent exchange and activation to remove unreacted species and trapped solvents.

• Washing: Use DMF, methanol or acetone to remove residual linkers.
• Solvent exchange: Replace high-boiling solvents with low-boiling ones (e.g., ethanol).
• Activation (Drying): Heat under vacuum to evacuate pores and achieve full surface area.

Improper activation can collapse the structure or reduce adsorption capacity.

5. From Lab-Scale to Industrial Scale

Scaling up MOF synthesis requires:

• Solvent recycling to reduce cost and waste
• Batch consistency and quality control
• Stability and reproducibility during long-term storage

Industrial Solutions Include:

• Using water or ethanol as greener solvents
• Adopting continuous flow or spray-drying processes
• Automation for mixing and temperature control

Industrial-scale MOFs are now available for gas storage, catalysis and CO₂ capture, bridging the gap between academic discovery and commercial application.

Representative MOFs and Their Synthetic Conditions

Related Articles:

What Are Metal Organic Frameworks (MOFs)?