Mn‐Oxygen Compounds Coordinated Ruthenium Sites with Deprotonated and Low Oxophilic Microenvironments for Membrane Electrolyzer‐Based H₂‐Production

Abstract

Among the platinum‐group metals, ruthenium (Ru), with a low water dissociation energy, is considered a promising alternative to substitute Pt for catalyzing hydrogen evolution reaction (HER). However, optimizing the adsorption–desorption energies of H* and OH* intermediates on Ru catalytic sites is extremely desirable but remains challenging. Inspired by the natural catalytic characteristics of Mn‐oxygen complex, this study reports to design Mn‐oxygen compounds coordinated Ru sites (MOC‐Ru) with deprotonated and low oxophilic microenvironments for modulating the adsorption–desorption of H* and OH* to promote HER kinetics. Benefiting from the unique advantages of MOC structures, including weakened HOH bond at interface, electron donation ability, and deprotonation capability, the MOC‐Ru exhibits extremely low overpotential and ultralong stability in both acidic and alkaline electrolytes. Experimental observations and theoretical calculations elucidate that the MOC can accelerate water dissociation kinetics and promote OH* desorption in alkaline conditions and trigger the long‐range H* spillover for H2‐release in acid conditions. The outstanding activity and stability of membrane electrolyzer display that the MOC‐Ru catalyst holds great potential as cathode for H2‐production. This study provides essential insights into the crucial roles of deprotonated and low oxophilic microenvironments in HER catalysis and offers a new pathway to create an efficient water‐splitting cathode.

Boosting Hydrogen Adsorption via Manipulating the d-Band Center of Ferroferric Oxide for Anion Exchange Membrane-Based Seawater Electrolysis

“…In addition, the XPS of Ru 3+ shows a positive shift of 0.3 eV for Ru/P–Fe 3 O 4 @IF, which can deduce that the doping of P lead to electron migration of Ru/P–Fe 3 O 4 @IF (Figure f). The O 1s XPS spectrum (Figure g) shows two peaks at 533.3 and 530.9 eV, which are attributed to adsorbed H 2 O, Ru–O, and Fe–O, respectively. , Moreover, the Fe–O peak intensity in the Ru–Fe 3 O 4 @IF and P–Fe 3 O 4 @IF spectrum is relatively lower than that in Ru/P–Fe 3 O 4 @IF, representing the stronger combination of Fe–O in Ru/P–Fe 3 O 4 @IF, which results in improved electrical conductivity in Fe 3 O 4. In summary, Ru and P exist in the form of Ru–O, Ru–P, and Fe–P coordination, and the doping of Ru and P significantly adjusts the electronic structure of Fe 3 O 4 , accumulating more electrons on the surface of Ru/P–Fe 3 O 4 @IF, which is more favorable for the adsorption of H* intermediates. − …”

Alkaline-earth-metal regulated metal carbides with bioinspired gradient OH spillover for efficient and long-lasting direct seawater electrolysis

“…As shown in the polarization curves, the higher current density of C–WC–RuMg than C–WC–Ru over the entire potential range can be attributed to the lower oxophilicity of C–WC–RuMg, which mitigates the accumulation of OH* on the Ru sites. 60 Thereafter, the local pH of the C–WC–RuMg cathode surface was measured using the rotating ring-disk electrode (RRDE) method at various applied potentials in 1.0 M PBS solution (bulk pH of 7.0) and contrasted with that of C–WC–Ru and the traditional carbon carrier (Fig. 4b, S12 and S13†).…”

Interfacial electron-engineered tungsten oxynitride interconnected rhodium layer for highly efficient all-pH-value hydrogen production

“…25,29,30 Therefore, optimizing the interfacial electronic structure and establishing accurate structure-property relationships for the supported metal catalysts are the key points for improving their performance for HER. 19,31,32 Based on the volcano curve of the calculated hydrogen adsorption energies, rhodium (Rh) has been considered as one of the most promising alternatives to Pt in HER. 33 Due to high intrinsic corrosion resistance to various media, Rh-based HER electrocatalysts are also available in all-pH-value electrolytes.…”

“…25,29,30 Therefore, optimizing the interfacial electronic structure and establishing accurate structure–property relationships for the supported metal catalysts are the key points for improving their performance for HER. 19,31,32…”