Simultaneous Tuning of the Microenvironment and Dissociation Kinetics of Interfacial Water on Electrocatalyst Toward Enhanced Alkaline Water Electrolysis

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Abstract Identifying strategies that can simultaneously modulate the microenvironment and dissociation kinetic of interfacial H 2 O in the Volmer step of alkaline water electrolysis is highly desirable while challenging toward advanced anion‐exchange membrane water electrolysis (AEMWE). Herein, a facile fluorine (F) doping strategy is reported with a high‐temperature shock (HTS) approach to tune the microenvironment of interfacial H 2 O together with reducing the H 2 O dissociation energy of IrNi alloy electrocatalyst supported on multi‐walled carbon nanotubes (MWCNTs), thus significantly enhancing the alkaline hydrogen evolution reaction (HER). Theoretical and experimental investigations collectively demonstrate that the F dopant can form a strong hydrogen bond with interfacial H 2 O, thus optimizing the arrangement and adsorption of interfacial H 2 O. Moreover, the electronic state of IrNi clusters can be modified by the F dopant, which reduces the H 2 O dissociation energy. Consequently, the IrNi alloy electrocatalyst supposed on F‐modified MWCNTs (IrNi/F‐MWCNTs) delivers outstanding performances for alkaline HER, which is much superior to the benchmark Pt/C electrocatalyst. More impressively, at an Ir mass loading of only 10 µg cm −2 , an AEMWE cell with IrNi/F‐MWCNTs as cathode achieves high current density of 1 A cm −2 at cell voltages of 1.82 V.

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