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Organic Chemistry, Retro-synthesis, Nanocrystal-based Electrodes, Heterogeneous Electrocatalytic Strategy, Schottky Heterojunctions, Direct Deprotonation Process
Abstract:
Activation of C − H bonds is maybe the central challenge in organic chemistry and usually the key step for
the retro-synthesis of functional natural products and medicines from abundant hydrocarbons due to the
high chemical stability of C − H bonds. Electrochemical methods are now recognized as a powerful
alternative for C − H activation, but this approach usually requires high overpotential and homogeneous
mediators. Here, we designed electron-deficient W2C nanocrystal-based electrodes to boost the
heterogeneous activation of C − H bonds under mild conditions via an additive-free, purely heterogeneous
electrocatalytic strategy. The electron density of W2C nanocrystals was 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 W2C surface, enabling a high turnover frequency (18.8 h− 1)
at a comparably low work potential (2 V versus SCE). The pronounced electron deficiency of the W2C
nanocatalysts substantially facilitates the direct deprotonation process to ensure long-term electrode
durability without self-oxidation. The eficient 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 whole process meets the requirements of atomic economy and electric energy utilization in
terms of sustainable chemical synthesis.
