Aqueous Electrocatalytic Reduction as a Low‐Carbon and Green Route for Chemical Synthesis and Environmental Remediation

Abstract

The green electricity‐driven electrocatalytic reduction of organic compounds in aqueous solution has merged as a sustainable and green platform for organic electrosynthesis, upcycling of chemical waste, and environmental remediation. Compared with the thermocatalytic hydrogenation process, the electrocatalytic reduction of organic compounds uses water as a proton source, which enables its operation at ambient conditions with simplified reaction schemes and significantly reduces operation cost and energy consumption. Most studies have demonstrated the development of electrocatalysts to boost the current efficiency, conversion, and product selectivity of the electrocatalytic reduction processes. Still, little attention has been paid to the mechanism (e. g., electron/proton transfer route) and related energetics behind the electrocatalytic reduction process. This Concept overviews the recent development of the electrocatalytic reduction systems for environmental remediation, pollutant upcycling, and valorization of biomass‐derived chemicals. This Concept highlights the underlying mechanisms and aims to provide instructive guidance on designing efficient and selective electrocatalytic systems.

Efficient and selective electrosynthesis of adiponitrile by electrohydrodimerization of acrylonitrile over a bismuth nanosheet modified electrode

“…6,8 In addition, EHD-AN also suffers from low product selectivity due to the diverse competing reactions, including the hydrogen evolution reaction (HER), early protonation of AN˙ − to form propionitrile (PN), trimerization of AN to form 1,3,6-tricyanohexane, and reductive oligomerization of AN. 5,7,25 To minimize the interference from these side reactions and thus achieve satisfactory selectivity towards ADN generation, several strategies have been explored, including the utilization of quaternary alkyl ammonium salt (QAS) as the electrolyte additive and the employment of electrode materials with high HER overpotentials, as well as a surface for the adsorption of AN with an appropriate adsorption configuration. 7,9,10 The use of QAS with a suitable substituting alkyl group as the electrolyte additive was demonstrated to be beneficial for increasing the solubility of AN and to minimize the HER and early protonation of AN˙ − .…”