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

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.