Catalysis

What is a catalyst?

Catalysis uses catalysts, chemicals capable of increasing the reaction rate and selectivity towards the products of interest by decreasing the activation energy of the limiting reaction step. The catalyst is not consumed in the course of the reaction and can therefore be reused in several reaction cycles, thus increasing process viability. The catalyst may undergo changes that result in deactivation or the reduction of its catalytic activity. In these cases, a regeneration step is necessary before it can be reused.

Catalysis solutions

At AIMPLAS, we work on the synthesis and modification of catalysts, and their subsequent use in catalytic processes to pursue different objectives:

• Synthesis of plastic materials that help reduce energy consumption and toxicity.
• Chemical recycling of plastics to obtain new value-added materials. Improving the performance of solvolysis, biological cracking, enzymatic recycling and pyrolysis processes.
• Conversion of CO₂ emissions and waste into fine chemicals, polymers and renewable biofuels.
• Enzymatic catalysis to achieve the sustainable synthesis of polymers as well as plastic degradation.

How do we do it?

• Custom Catalyst Design and Synthesis
  Development of catalysts tailored to specific processes and applications, optimising their composition, structure, and functional properties. This enables improved reaction efficiency, selectivity towards desired products, and catalyst stability under real operational conditions.
• Post-Synthesis Catalyst Modification
  Modification of catalysts through thermal and/or surface treatments to adjust their structural or compositional properties. These modifications allow optimisation of catalytic activity, enhancement of material stability, or adaptation of existing catalysts to new process conditions.
• Catalyst Shaping
  Development of processes for shaping powdered catalysts into structured formats such as pellets, extrudates, or monoliths suitable for reactor implementation, improving mechanical strength, material handling, and operational performance.
  • Granulation
  • Foaming
  • Extrusion
  • Pelletisation
• Scale-Up of Catalyst Synthesis Processes (up to Pilot Scale)
  Adaptation and optimisation of catalyst synthesis processes from laboratory scale (100 mL) to pilot scale (100 L), ensuring process reproducibility and consistency of material properties. This step allows validation of the catalyst under conditions closer to industrial application.
• Catalyst Characterisation
  Study of physicochemical properties and catalytic behaviour using advanced characterisation techniques, enabling understanding of the relationship between material structure and performance, and optimisation of its application performance.

Types of catalysis

The chemistry of catalysts is very broad. They can be classified based on whether or not they are in the same phase as the reactants:

• Homogeneous catalysis
• Heterogeneous catalysis
• Heterogenized catalysis: considered to be a combination of the above.
• Enzymatic catalysis: it differs from the previous type because the catalyst used is an enzyme.

Heterogeneous catalysis

Heterogeneous catalysis occurs when the catalyst is in a different phase from the reagents and products. These phases are generally solid-liquid and solid-gas. The reaction takes place on the surface of the catalyst, where active sites are located. Therefore, the smaller the particle size of the catalyst, the larger the surface area for a given mass and the greater the catalyst activity.

Heterogeneous catalysis has high specificity, given that activity occurs only at the active sites on the surface of the catalyst. Although their initial cost is often greater than homogeneous catalysts, these catalysts are highly stable and easily recoverable, which means they can be reused in several reaction cycles, thus reducing their economic and environmental impact. It is sometimes necessary to regenerate the catalyst before it can be reused.

Heterogenized catalysis

Heterogenized catalysis makes use of catalysts with surface phenomena, i.e. they are not in the same phase, but can generate compounds that dissolve, which are involved in the homogeneous catalytic cycle and regenerate the heterogeneous catalysts, thus creating a synergy between heterogeneous and homogeneous properties that enhances the catalytic effect.

Enzymatic catalysis

The catalysts used are enzymes, biological catalysts found in nature, which are often proteins (amino acid polymers). Enzymatic catalysis can be carried out homogeneously and heterogeneously and is used in a wide range of reactions (e.g. hydrolysis, ring-opening polymerization, condensation). One of the great advantages of enzymes is their high selectivity. Immobilized enzymes are easily recoverable and reusable.