Atomically Local Electric Field Induced Interface Water Reorientation for Alkaline Hydrogen Evolution Reaction

Abstract

The slow water dissociation process in alkaline electrolyte severely limits the kinetics of HER. The orientation of H2O is well known to affect the dissociation process, but H2O orientation is hard to control because of its random distribution. Herein, an atomically asymmetric local electric field was designed by IrRu dizygotic single‐atom sites (IrRu DSACs) to tune the H2O adsorption configuration and orientation, thus optimizing its dissociation process. The electric field intensity of IrRu DSACs is over 4.00×1010 N/C. The ab initio molecular dynamics simulations combined with in situ Raman spectroscopy analysis on the adsorption behavior of H2O show that the M−H bond length (M=active site) is shortened at the interface due to the strong local electric field gradient and the optimized water orientation promotes the dissociation process of interfacial water. This work provides a new way to explore the role of single atomic sites in alkaline hydrogen evolution reaction.

Metal-support interactions alter the active species on IrOx for electrocatalytic water oxidation

“…In some reported works, modulating the dissociation of H 2 O at reactive sites and metal–oxygen coupling was related to the reaction kinetics, and thus it impacted the OER activity. 44,45…”

“…In some reported works, modulating the dissociation of H 2 O at reactive sites and metal-oxygen coupling was related to the reaction kinetics, and thus it impacted the OER activity. 44,45 To further understand the connection between the absorption of *O and O-O coupling, Au@MnO 2 -IrO x -(b) NPs were prepared with a higher Ir loading for in situ SERS tests. In Fig.…”

Boosting Alkaline Hydrogen Evolution Reaction through Water Structure Manipulation

“…The recent work by Fu, Wang, Zhang, Cortés, Liu, and co‐workers opens a new avenue for improving alkaline HER performance by co‐doping two single metal atoms into cobalt phosphides (CoP), resulting in iridium and ruthenium doped dizygotic single‐atom sites (IrRu DSACs) [9] . A unique feature of these IrRu DSACs is that adjacently co‐doped Ir and Ru atoms lead to a stronger variation in local charge density (about 4.00 eÅ −2 ), nearly twice as big as those doped with single Ir or Ru.…”

“… The new strategy for improving alkaline HER proposed by Wang, Zhang, Cortés, Liu, and co‐workers, based on manipulating the water structure through the introduction of a local electric field via doping [9] . The left panel is the electrode‐electrolyte interface on pristine CoP, and the right panel is that for the IrRu DSAC supported by CoP.…”

Ni/TiO2 heterostructures derived from phase separation for enhanced electrocatalysis of hydrogen evolution and biomass oxidative upgrading in anion exchange membrane electrolyzers

“…10,12 Recently, increasing studies have revealed that the water structure and proton transfer in the electric double layer also play an important role in the HER process. 17,[20][21][22][23][24][25] Chen et al found that the water distribution and the connectivity of hydrogen bond networks in the electric double layer are responsible for the greatly reduced kinetics of hydrogen electrocatalysis in alkaline solutions. 22 It should be noted that most studies in this area are focused on noble metal-based catalysts, and there is an obvious difference between noble metal-based and noble metal-free catalysts in the kinetic pH effect on HERs.…”