Cu<sup>δ+</sup> Site-Enhanced Adsorption and Crown Ether-Reconfigured Interfacial D<sub>2</sub>O Promote Electrocatalytic Dehalogenative Deuteration
Meng He, Haotian Wang, Chuanqi Cheng, Rui Li, Cuibo Liu, Ying Gao, Bin Zhang
Abstract
Electrocatalytic dehalogenative deuteration is a sustainable method for precise deuteration, whereas its Faradaic efficiency (FE) is limited by a high overpotential and severe D 2 evolution reaction (DER). Here, Cu δ+ site-adjusted adsorption and crown ether-reconfigured interfacial D 2 O are reported to cooperatively increase the FE of dehalogenative deuteration up to 84% at −100 mA cm –2 . Cu δ+ sites strengthen the adsorption of aryl iodides, promoting interfacial mass transfer and thus accelerating the kinetics toward dehalogenative deuteration. The crown ethers disrupt the hydration effect of K·D 2 O and reconstruct the hydrogen bond with the interfacial D 2 O, lowering the content K·D 2 O of the electric double layer and hindering the interaction between D 2 O and the cathode, thus inhibiting the kinetics of the competitive DER. A linear relationship between the matched sizes of crown ethers and alkali metal cations is demonstrated for universally increasing FEs. This method is also suitable for the deuteration of various halides with high easily reducible functional group compatibility and improved FEs at −100 mA cm –2 .