Microenvironment regulation breaks the Faradaic efficiency-current density trade-off for electrocatalytic deuteration using D<sub>2</sub>O.

He, Meng; Li, Rui; Cheng, Chuanqi; Liu, Cuibo; Zhang, Bin · Nat Commun · 2024

basic_science · Level V

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Abstract

The high Faradaic efficiency (FE) of the electrocatalytic deuteration of organics with D<sub>2</sub>O at a large current density is significant for deuterated electrosynthesis. However, the FE and current density are the two ends of a seesaw because of the severe D<sub>2</sub> evolution side reaction at nearly industrial current densities. Herein, we report a combined scenario of a nanotip-enhanced electric field and surfactant-modified interface microenvironment to enable the electrocatalytic deuteration of arylacetonitrile in D<sub>2</sub>O with an 80% FE at -100 mA cm<sup>-2</sup>. The increased concentration with low activation energy of arylacetonitrile due to the large electric field along the tips and the accelerated arylacetonitrile transfer and suppressed D<sub>2</sub> evolution by the surfactant-created deuterophobic microenvironment contribute to breaking the trade-off between a high FE and large current density. Furthermore, the application of our strategy in other deuteration reactions with improved Faradaic efficiencies at -100 mA cm<sup>-2</sup> rationalizes the design concept.