Multiphase Methods in Organic Electrosynthesis

Marken, Frank; Wadhawan, Jay D

Abstract

Conspectus With water providing a highly favoured solution environment for industrial processes (and in biological processes), it is interesting to develop water-based electrolysis processes for the synthesis and conversion of organic and biomass-based molecules. Molecules with low solubility in aqueous media can be dispersed/solubilised (i) by physical dispersion tools (by milling, by power ultrasound, or by high shear ultra-turrax processing), (ii) in some cases by pressurising/super-saturation (e.g. for gases), (iii) by adding co-solvents or "carriers" such as chremophor EL, or (iv) by adding surfactants to generate micelles, microemulsions, and/or stabilised biphasic conditions. This review examines and compares methodologies to bring the dispersed or multi-phase system into contact with an electrode. Both the microscopic process based on the individual particle impact as well as the overall electro-organic transformation are of interest. Distinct mechanistic cases for multi-phase redox processes are considered. Most traditional electroorganic transformations are performed in homogeneous solution with reagents, products, electrolyte, and possibly mediators or redox catalysts all in the same (usually organic) solution phase. This may lead to challenges in the product separation step and in the re-use of solvents and electrolytes. When exploiting aqueous electrolyte media, reagents and products (or even electrolyte) may be present as microdroplets or nanoparticles. Redox transformations then occur during interfacial "collisions" under multiphase conditions or

• Journal Article Type: Review
• Journal: Accounts of chemical research
• Print ISSN: 0001-4842
• Publisher: American Chemical Society
• Peer Reviewed: Peer Reviewed
• APA6 Citation: Marken, F., & Wadhawan, J. D. (in press). Multiphase Methods in Organic Electrosynthesis. Accounts of chemical research, https://doi.org/10.1021/acs.accounts.9b00480
• DOI: https://doi.org/10.1021/acs.accounts.9b00480
• Publisher URL: https://pubs.acs.org/doi/10.1021/acs.accounts.9b00480