7/22/2023 0 Comments Ev nova license code 2018![]() The significant progress reported using well-designed reaction-specified electrodes in improving the catalytic activity for water splitting, nitrogen reduction reactions, and even carbon dioxide reduction reactions 30– 33 further manifests the huge gap between the design of electrode materials and the requirements of sustainable electrochemical organic synthesis. Principally, the preparation of cost-effective and active electrode materials is at least as important as the development of a methodology for selective C–H bonds activation 22– 29, and only non-targeted, commercial first-generation electrodes (such as carbon rod, platinum, and reticulated vitreous carbon) are applied as the current collectors in electrochemical organic synthesis at the moment. The current strategies to boost the transformation of specific substrates mainly rely on the involvement of functional additives 11, 20 (e.g., organic ligands, bases, and mediators), a high work potential, and/or sacrificial transition metal electrodes 21, which all will severely limit real-industry applications. Most of these reactions have a high atom economy and excellent compatibility with flow reactors for continuous synthesis 18, 19. Pioneering works of electrochemical synthesis using homogeneous catalysts have demonstrated the advantages of this technique for C–H activation 11– 13, which includes selective oxidation 14, amination 15, epoxidation 16, and dehydrogenative coupling reactions 17. As a result, sustainable strategies are highly desirable to further decrease the economic and environmental footprints of C−H activation processes.Įlectrochemical transformation is recognized as an environmentally friendly method for the production of various functional molecules driven by electricity under mild conditions 9– 11. ![]() Moreover, the as-formed side product water from the cleavage of C–H bonds via oxydehydrogenation is free of value. However, the relative stability of C( sp 3)−H bonds adjacent to aromatic rings make C–H activation quite challenging, and either extreme and rather toxic oxidants as chromium or selenium compounds or noble-metal-catalysts (based on rhodium or palladium) at high temperatures have to be applied to obtain acceptable conversions 6– 8. As a typical and important transformation path of C–H bonds, selective dehydrogenation of C–H bonds have been widely used for the production of high value-added compounds such as alcohols, and ketones, and ethers 3– 5. The whole process meets the requirements of atomic economy and electric energy utilization in terms of sustainable chemical synthesis.ĭirect activation of C–H bonds via selective oxidation of hydrocarbons is of great interest for organic hydrocarbons 1, 2. The efficient oxidation process also boosts the balancing hydrogen production from as-formed protons on the cathode by a factor of 10 compared to an inert reference electrode. The pronounced electron deficiency of the W 2C nanocatalysts substantially facilitates the direct deprotonation process to ensure electrode durability without self-oxidation. The electron density of W 2C nanocrystals is tuned by constructing Schottky heterojunctions with nitrogen-doped carbon support to facilitate the preadsorption and activation of benzylic C–H bonds of ethylbenzene on the W 2C surface, enabling a high turnover frequency (18.8 h −1) at a comparably low work potential (2 V versus SCE). Here, we design electron-deficient W 2C nanocrystal-based electrodes to boost the heterogeneous activation of C–H bonds under mild conditions via an additive-free, purely heterogeneous electrocatalytic strategy. Electrochemical methods are a powerful alternative for C–H activation, but this approach usually requires high overpotential and homogeneous mediators. The activation of C–H bonds is a central challenge in organic chemistry and usually a key step for the retro-synthesis of functional natural products due to the high chemical stability of C–H bonds.
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