Recent advances in the recycling of homogeneous catalysts using membrane separation

Abstract

Membrane filtration is an attractive approach for soluble catalyst recycling. Applications of nanofiltration have demonstrated their great potential as a method for process intensification in enzyme, organo-, and homogeneous catalysis, both in laboratory practice and on an industrial scale. Selected, recent advances in catalyst recovery by means of membrane filtration are discussed, together with their implication for future developments. These examples demonstrate that this strategy is applicable in many different transformations.

Magnetically Separable and Sustainable Nanostructured Catalysts for Heterogeneous Reduction of Nitroaromatics

“…The removal of residual catalytic species from the reaction mixture is always challenging, even with the use of numerous techniques, such as chromatography, distillation or extraction. In contrast, heterogeneous catalysts have the advantages of recovery and reuse after the completion of the reactions and green chemical processes [12][13][14]. Therefore, several procedures have been developed to synthesize durable and reusable heterogeneous catalysts for the reduction of nitro compounds.…”

A Microfluidic System for the Continuous Recycling of Unmodified Homogeneous Palladium Catalysts through Liquid/Liquid Phase Separation

“…However, their industrial applications are limited by the difficulties associated with catalyst recovery and recycling 1b,c. As a result, many strategies have been devised to overcome those challenges,2 including immobilizing the catalysts onto solid or liquid supports through structural modifications,3–7 enlarging the catalysts for ultra‐ or nanofiltration,8 and the controlled variation of their solubility 9. 10 Although catalyst leaching remains a general challenge, some of these methods have been successful.…”

Heterogeneous Suzuki Cross-Coupling Reaction Catalyzed by Magnetically Recyclable Nanocatalyst

“…Furthermore, the unprotected Pd NPs are usually unstable and coagulation is inevitable during the catalytic reactions. [10][11][12] The immobilization of catalysts NPs on solid supports has therefore attracted a lot of attention to circumvent recycling and instability probelms. [13][14][15][16] The catalyst NPs grafted or immobilized on the surface of the supports also provide accessible diffusion to reagents, and result in more effective chemical reactions.…”