The granular and porous structure of the catalyst resin makes it suitable for gas-phase and liquid-phase reactions, as well as for non-aqueous systems, and plays an important role in catalyzing organic synthesis reactions. Its wide range of applications is second only to molecular sieves and oxide catalysts. Catalytic resin is used as a solid acid and solid base catalyst. Its acid and basic functional groups are similar to those of sulfuric acid, hydrochloric acid, sodium hydroxide and other catalysts in a homogeneous catalytic reaction system. It is suitable for packing tower operation and can realize continuous production. In addition, because the polymer backbone of the resin will swell in many reaction media, it is conducive to the proximity of the reactants and the catalytic active sites, and the reaction microenvironment is very close to a homogeneous reaction system. Therefore, the resin-supported acid, alkaline catalysts also have great advantages compared with acid and alkali catalysts immobilized on inorganic supports such as silica gel, alumina, aluminosilicate or zeolite.
Researches
Catalyst resins can be used as catalysts for the production of phenolic oligomers. Phenolic oligomers are widely used in various industries due to their excellent mechanical strength and high heat resistance. Traditional synthesis methods use basic KOH (NaOH) and acid (p-toluenesulfonic acid) catalysts in the methylolation and esterification stages, respectively. Due to the need to neutralize the catalyst, the salt in the reaction mixture is difficult to remove, the synthesized product is contaminated, and repeated washing and filtration are required, which further leads to a large amount of waste. The ionic resin catalyst can simplify the synthesis technology, reduce the amount of waste water, and can be reused, which ultimately leads to a significant reduction in product cost.( Tuzova S Y, Antipov E M., 2015) Conventional homogeneous catalytic esterification reactions of carboxylic acids with alcohols are difficult to separate the catalyst from the reaction mixture, side reactions may occur and the reactor may corrode. To overcome this problem, solid acid catalysts have been introduced. Among the many solid catalysts, ion exchange resins are the most commonly used for esterification reactions. The catalyst can be recovered by simple filtration after several catalytic runs, cleaned and then used again.( Biswas K, et al., 2020)
Typical Applications
- Esterification
- Transesterification
- Acetalization
- Etherification of olefins and alcohols
- Alkylation
- Alcohol dehydration, etc.
References
- Tuzova S Y, Antipov E M. Ion exchange resins as catalysts for synthesizing phenol-formaldehyde oligomers[J]. Theoretical Foundations of Chemical Engineering, 2015.
- Biswas K, et al. Ion-exchange Resins and Polypeptide Supported Catalysts: A Critical Review[J]. Current Green Chemistry, 2020.
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