Alkaline Hydrogen Evolution Reaction Research Articles

Low content of Ni‐Pt nanoparticles decorated carbon nanofibers as efficient electrocatalyst for hydrogen evolution reaction

AbstractBackgroundAmong various technologies, electrochemical water splitting is one of the most effective and promising techniques for obtaining hydrogen fuel. The low content of nickel–platinum (Ni‐Pt) nanoparticles (NPs) decorated on carbon nanofibers (CNFs) have been developed by the electrospinning technique and subsequent carbonization process for use in an effective hydrogen evolution reaction (HER) in both acidic and alkaline mediums.ResultsThe Ni‐Pt ions are reduced to Ni‐Pt NPs during the carbonization process, while polyacrylonitrile nanofibers are simultaneously changed into carbon nanofibers. Field emission scanning electron microscopy (FE‐SEM) with energy dispersive X‐ray (EDX) and transmission electron microscopy (TEM) analysis of the prepared Ni‐Pt/CNFs shows that the low content of Ni and Pt NPs is evenly dispersed on the carbon nanofibers. This implies that for close contacts, there is an effective charge transfer between the NPs and the CNFs system. The obtained Ni‐Pt/CNFs exhibit enhanced HER performance along with onset potential (η1/23 mV in ~0 pH and η1/33 mV in ~14 pH) and overpotential (η10/128 mV in pH ~0 and η10/152 mV in pH ~14) versus RHE. Furthermore, stability for a long time was attained without considerable decay by 24 h. The turnover frequency (TOF) value was 3.431 s−1 in acidic and 1.174 s−1 in alkaline electrolytes.ConclusionThe enhanced HER performance could be ascribed to the synergetic effects between the carbon fibers and the Ni‐Pt NPs. This work demonstrates an easy technique for producing highly effective electrocatalysts for water splitting and has significant implications for renewable energy. © 2024 Society of Chemical Industry (SCI).

Synergistic effect of Pd single atoms and nanoparticles deposited on carbon supports by ALD boosts alkaline hydrogen evolution reaction

The synergistic effects between carbon supports and noble metal species of an electrocatalyst are known to effectively boost the alkaline hydrogen evolution reaction (HER). Herein, Atomic Layer Deposition (ALD) was employed to decorate carbon papers with Pd species comprising single atoms (SAs) and nanoparticles (NPs). Transmission electron microscopy analysis revealed the metallic nature and coexistence of Pd as SAs and NPs. The results of X-ray photoelectron spectroscopy supported the evidenced SA species, manifested as the Pd+2. An increase in the electrochemical active surface area from 12.98 to 413.48 cm−2 was evidenced with increasing ALD cycles from 30 to 300c Pd and remained unchanged until 600c Pd. The exceptional overpotential for CP 600c Pd exhibits the lowest value of 4.55 mV, compared to previous reports for Pd electrocatalysts in a non-acidic environment, and confirms the synergistic effect of Pd SAs and NPs that plays a major role in enhancing alkaline HER.

Pt Single Atoms Supported on Defect Ceria as an Active and Stable Dual-Site Catalyst for Alkaline Hydrogen Evolution.

This work evaluates the feasibility of alkaline hydrogen evolution reaction (HER) using Pt single-atoms (1.0 wt %) on defect-rich ceria (Pt1/CeOx) as an active and stable dual-site catalyst. The catalyst displayed a low overpotential and a small Tafel slope in an alkaline medium. Moreover, Pt1/CeOx presented a high mass activity and excellent durability, competing with those of the commercial Pt/C (20 wt %). In this picture, the defective CeOx is active for water adsorption and dissociation to create H* intermediates, providing the first site where the reaction occurs. The H* intermediate species then migrate to adsorb and react on the Pt2+ isolated atoms, the site where H2 is formed and released. DFT calculations were also performed to obtain mechanistic insight on the Pt1/CeOx catalyst for the HER. The results indicate a new possibility to improve the state-of-the-art alkaline HER catalysts via a combined effect of the O vacancies on the ceria support and Pt2+ single atoms.

Climbing the Hydrogen Evolution Volcano with a NiTi Shape Memory Alloy.

Alkaline water electrolysis is a sustainable way to produce green hydrogen using renewable electricity. Even though the rates of the cathodic hydrogen evolution reaction (HER) are 2-3 orders of magnitude less under alkaline conditions than under acidic conditions, the possibility of using non-precious metal catalysts makes alkaline HER appealing. We identify a novel and facile route for substantially improving HER performance via the use of commercially available NiTi shape memory alloys, which upon heating undergo a phase transformation from the monoclinic martensite to the cubic austenite structure. While the room-temperature performance is modest, austenitic NiTi outperforms Pt (which is the state-of-the-art HER electrocatalyst) in terms of current density by ≤50% at 80 °C. Surface ensembles presented by the austenite phase are computed with density functional theory to bind hydrogen more weakly than either metallic Ni or Ti and to have binding energies ideally suited for HER.

Enhanced alkaline hydrogen evolution reaction of MoO2/Ni3S2 nanorod arrays by interface engineering

Interface engineering is verified as an efficient strategy for enhancing the intrinsic activity of transition metal-based electrocatalysts in alkaline hydrogen evolution reaction (HER). Here, the heterostructural MoO2/Ni3S2 nanorod arrays fabricated on nickel foam (MoO2/Ni3S2/NF) are produced by a straightforward and effective hydrothermal approach. Benefiting from interfacial effect and self-supported structure, MoO2/Ni3S2/NF electrocatalyst exhibits remarkable HER catalytic properties and durability with a low overpotential of 74.0 mV for achieving a current density of 10 mA cm−2 in 1.0 M KOH, as well as a long-term stability without obvious attenuation. Density functional theory (DFT) calculations reveal electron transfer at the interface domain reduces the energy barrier of the water dissociation step and optimizes H adsorption capability, thereby expediting HER kinetics in alkaline media. This work provides a viable strategy based on interfacial engineering for designing high-efficient HER electrocatalysts.

Precisely tuning the Ni3N/Pt interface to boost the catalytic activity of alkaline hydrogen evolution reaction

The hydrogen evolution reaction (HER) in alkaline solutions does not access H* directly, resulting in a slower reaction kinetics compared to that in acidic solutions. Here, we report a Cr-doped Ni3N/Pt heterostructure that provides additional active sites to produce H* via the water-cleaving step, in addition to the intrinsic active Pt site for H* absorption. It is demonstrated that the Cr dopant can modulate the charge redistribution between Ni3N and Pt interface, lowering the energy barrier of both the Volmer step and the following Heyrovsky step. As a result, the prepared Cr-Ni3N/Pt catalyst achieves an extreme low overpotential of 20 mV to deliver a current density of 10 mA/cm2 under alkaline conditions, which is significantly better than the commercial Pt/C catalyst (45 mV). Density Functional Theory (DFT) further reveals that the Cr-modified Ni3N/Pt interface undergoes electronic orbital hybridization, enhancing the water adsorption and dissociation processes on the Ni sites. This work presents the feasibility of the electronic structure modulation in low-platinum catalysts, which provides an effective strategy for the design of electrocatalysts used in multi-step reactions.

Strategically Designed Pd-Induced Changes in Alkaline Hydrogen Evolution Reaction and Oxygen Evolution Reaction Performances of Electrochemical Water Oxidation by the Galvanically Synthesized MoO2/MoO3 Composite Thin Film.

Electrochemical water oxidation is believed to be an effective pathway to produce clean, carbon-free, and environmentally sustainable green energy. In this work, we report a simple, easy-to-construct, facile, low-cost, and single-step galvanic technique to synthesize a Pd-supported temperature-assisted MoOx thin film nanocomposite for effective water oxidation. The most suitable nanocomposite exhibits very low overpotential at 10 mA/cm2 with smaller Tafel slope values for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) processes in an alkaline medium. The formation of a metal oxide-metal junction accelerates the growth of more active sites, promoting induced electronic synergism at the MoOx-Pd interface. This endows higher electrical conductivity and faster electron transfer kinetics, thus accelerating the faster water dissociation reaction following the Tafel-Volmer mechanism to boost the HER process in an alkaline medium. The excellent electrochemical HER and OER performances of our electrocatalyst even supersede the accomplishments of the benchmark catalysts Pt/C and RuO2. Moreover, neither of these two catalysts demonstrates both catalytic reactions, i.e., HER and OER at the same time, which have been observed for our synthesized catalyst. Our findings illustrate the potential of a thin-film MoOx-Pd nanocomposite to be an exceedingly effective electrocatalyst developed by interface engineering strategies. This also provides insight into designing several other semiconductor composite catalysts using simple synthesis techniques for highly efficient HER/OER processes that could be alternatives to benchmark electrocatalysts for water electrolysis.

Platinum-Ruthenium Dual-Atomic Sites Dispersed in Nanoporous Ni0.85Se Enabling Ampere-Level Current Density Hydrogen Production.

Alkaline anion-exchange-membrane water electrolyzers (AEMWEs) using earth-abundant catalysts is a promising approach for the generation of green H2. However, the AEMWEs with alkaline electrolytes suffer from poor performance at high current density compared to proton exchange membrane electrolyzers. Here, atomically dispersed Pt-Ru dual sites co-embedded in nanoporous nickel selenides (np/Pt1Ru1-Ni0.85Se) are developed by a rapid melt-quenching approach to achieve highly-efficient alkaline hydrogen evolution reaction. The np/Pt1Ru1-Ni0.85Se catalyst shows ampere-level current density with a low overpotential (46mV at 10mAcm-2 and 225mV at 1000mAcm-2), low Tafel slope (32.4mVdec-1), and excellent long-term durability, significantly outperforming the benchmark Pt/C catalyst and other advanced large-current catalysts. The remarkable HER performance of nanoporous Pt1Ru1-Ni0.85Se is attributed to the strong intracrystal electronic metal-support interaction (IEMSI) between Pt-Se-Ru sites and Ni0.85Se support which can greatly enlarge the charge redistribution density, reduce the energy barrier of water dissociation, and optimize the potential determining step. Furthermore, the assembled alkaline AEMWE with an ultralow Pt and Ru loading realizes an industrial-level current density of 1Acm-2 at 1.84volts with high durability.

Construction of heterophase MoOx/Ru assisted by self-assembled carboxymethylcellulose-Ru3+ nanosheet for improved alkaline hydrogen evolution

The hydrogen evolution reaction (HER) in alkaline medium is much sluggish than that in acidic medium due to the limited water dissociation step, thus accelerating the water dissociation kinetics is critical. Herein, we designed a MoOx species-modified ruthenium nanoparticle catalyst (MoOx/Ru/C-3) based on the unique electrostatic interaction between carboxymethylcellulose sodium salt (CMC) and metal ions, where an heterophase structure is formed between MoOx and Ru. The obvious electronic interaction between them allows the formation of synergistic promotion relationship involving the water dissociation on MoOx and the adsorbed hydrogen recombination on Ru. At a metal loading of 6.98 μgRu cm-2 geo, the overpotential of 82 mV is just required to reach a current density of 10 mA cm−2, exhibiting a significantly better apparent electrochemical activity than Ru/C (98 mV) without introduction of MoOx, which demonstrates superior or comparable alkaline HER activity to the recently reported Ru-based electrocatalysts. Meanwhile, the overpotential for Ru/C increased by 113 mV after 24 h of chronopotentiometric test, whereas only 61 mV elevates for MoOx/Ru/C-3, and even just 98 mV generates after 120 h. Thereof, introduction of MoOx species into Ru matrix can also markedly improve the electrochemical stability. The proposed material construction strategy in this study provides a feasible idea for the rational design of highly cost-performance alkaline hydrogen evolution catalysts.

Constructing Symmetry-Mismatched RuxFe3-xO4 Heterointerface-Supported Ru Clusters for Efficient Hydrogen Evolution and Oxidation Reactions.

Ru-related catalysts have shown excellent performance for the hydrogen evolution reaction (HER) and hydrogen oxidation reaction (HOR); however, a deep understanding of Ru-active sites on a nanoscale heterogeneous support for hydrogen catalysis is still lacking. Herein, a click chemistry strategy is proposed to design Ru cluster-decorated nanometer RuxFe3-xO4 heterointerfaces (Ru/RuxFe3-xO4) as highly effective bifunctional hydrogen catalysts. It is found that introducing Ru into nanometric Fe3O4 species breaks the symmetry configuration and optimizes the active site in Ru/RuxFe3-xO4 for HER and HOR. As expected, the catalyst displays prominent alkaline HER and HOR performance with mass activity much higher than that of commercial Pt/C as well as robust stability during catalysis because of the strong interaction between the Ru cluster and the RuxFe3-xO4 support, and the optimized adsorption intermediate (Had and OHad). This work sheds light on a promsing approach to improving the electrocatalysis performance of catalysts by the breaking of atomic dimension symmetry.

Grain Boundary Tailors the Local Chemical Environment on Iridium Surface for Alkaline Electrocatalytic Hydrogen Evolution

AbstractEven though grain boundaries (GBs) have been previously employed to increase the number of active catalytic sites or tune the binding energies of reaction intermediates for promoting electrocatalytic reactions, the effect of GBs on the tailoring of the local chemical environment on the catalyst surface has not been clarified thus far. In this study, a GBs‐enriched iridium (GB−Ir) was synthesized and examined for the alkaline hydrogen evolution reaction (HER). Operando Raman spectroscopy and density functional theory (DFT) calculations revealed that a local acid‐like environment with H3O+ intermediates was created in the GBs region owing to the electron‐enriched surface Ir atoms at the GBs. The H3O+ intermediates lowered the energy barrier for water dissociation and provided enough hydrogen proton to promote the generation of hydrogen spillover from the sites at the GBs to the sites away from the GBs, thus synergistically enhancing the hydrogen evolution activity. Notably, the GB−Ir catalyst exhibited a high alkaline HER activity (10 mV @ 10 mA cm−2, 20 mV dec−1). We believe that our findings will promote further research on GBs and the surface science of electrochemical reactions.

Grain Boundary Tailors the Local Chemical Environment on Iridium Surface for Alkaline Electrocatalytic Hydrogen Evolution.

Even though grain boundaries (GBs) have been previously employed to increase the number of active catalytic sites or tune the binding energies of reaction intermediates for promoting electrocatalytic reactions, the effect of GBs on the tailoring of the local chemical environment on the catalyst surface has not been clarified thus far. In this study, a GBs-enriched iridium (GB-Ir) was synthesized and examined for the alkaline hydrogen evolution reaction (HER). Operando Raman spectroscopy and density functional theory (DFT) calculations revealed that a local acid-like environment with H3 O+ intermediates was created in the GBs region owing to the electron-enriched surface Ir atoms at the GBs. The H3 O+ intermediates lowered the energy barrier for water dissociation and provided enough hydrogen proton to promote the generation of hydrogen spillover from the sites at the GBs to the sites away from the GBs, thus synergistically enhancing the hydrogen evolution activity. Notably, the GB-Ir catalyst exhibited a high alkaline HER activity (10 mV @ 10 mA cm-2 , 20 mV dec-1 ). We believe that our findings will promote further research on GBs and the surface science of electrochemical reactions.

In-situ electrochemical self-reconstruction of permeable Ni(OH)2/Pt hybrid for accelerating alkaline hydrogen evolution

Pt-based hybrid materials are demonstrated to be the most effective catalysts for alkaline hydrogen evolution reactions (HER) due to the synergy effect of heterogeneous interfaces. However, the heterogeneous interfaces are often constructed at the sacrifice of the electrochemical active surface area to cause relatively lower HER activity than expected. Herein, a permeable Ni(OH)2 layer and strained Pt atoms heterogeneous interface with enhanced electrocatalytic activity and minimal loss of active surface sites have been created by using an in-situ electrochemical self-reconstruction strategy. The permeable Ni(OH)2 layer promotes H2O dissociation without blocking proton contact with the active Pt sites. This unique design creates a favorable local acid-like environment that results in an ultra-high mass activity of 17.8 A mgPt−1 at an overpotential of 70 mV, which is 20.5 times superior to that of the commercial Pt/C catalyst and higher than those of the previously reported Pt-based catalysts. Meanwhile, the HER overpotential displays as low as 15 mV at 10 mA cm−2, showing superior HER efficiency and representing one of the optimal Pt-based HER catalysts in alkaline solution. In-situ Raman spectroscopy and DFT calculations prove that the interfacial synergistic interaction between permeable Ni(OH)2 layer and strained Pt atoms can significantly promote the H2O dissociation and the H2 formation. This electrochemical self-reconstruction method provides an effective and facile strategy for optimizing the electronic structure, electrocatalytic activity, and mass activity of active Pt atoms to develop efficient Pt-based heterostructure electrocatalysts.

Multi‐Interface Engineering of Self‐Supported Nickel/Yttrium Oxide Electrode Enables Kinetically Accelerated and Ultra‐Stable Alkaline Hydrogen Evolution at Industrial‐Level Current Density

AbstractThe development of highly active and robust non‐noble‐metal electrocatalysts for alkaline hydrogen evolution reaction (HER) at industrial‐level current density is the key for industrialization of alkaline water electrolysis. Herein, a superhydrophilic self‐supported Ni/Y2O3 heterostructural electrocatalyst is constructed by a high‐temperature selective reduction method, which demonstrates excellent catalytic performance for alkaline HER at high current density. Concretely, this catalyst can drive 10 mA cm−2 at a low overpotential of 61.1 ± 3.7 mV, with a low Tafel slope of 52.8 mV dec−1. Moreover, it also shows outstanding long‐term durability at high current density of 1000 mA cm−2 for 500 h in 1 m KOH, evidently exceeding the metallic Ni and Pt/C(20%) catalysts. The superior HER activity can be attributed to the multi‐interface engineering of the Ni/Y2O3 electrode. Construction of Ni/Y2O3 heterogeneous interface with dual active sites lowers the energy barrier of water dissociation and optimizes the hydrogen adsorption energy, thus synergistically accelerating the overall HER kinetics. Also, its superhydrophilic self‐supported electrode structure with the firm electrocatalyst‐substrate interface and weakened electrocatalyst‐bubble interfacial force ensures rapid charge transfer, prevents catalyst shedding, and expedites the H2 gas bubble release timely, further enhancing the catalytic activity and stability at high current density.

Interface Engineering with the Coupling of a 3D Porous Structure Enables MoP2-NiCoP Heterostructure Nanosheets for Enhanced Alkaline Hydrogen Evolution Reaction.

One of the crucial parts of the electrochemically focused energy conversion and storage system is the hydrogen evolution reaction. The further exploration of electrocatalysts made of nonprecious metals could help to bring the technology closer to industrialization. Here, we present an effective hydrogen evolution reaction (HER) electrocatalyst that employs hydrothermal and phosphorization steps to create three-dimensional (3D) porous MoP2-NiCoP heterostructure nanosheets on nickel foam (MoP2-NiCoP/NF). H2O-dissociation and H-adsorption were effectively achieved due to the distinctive interface engineering between NiCoP and MoP2, which functions as a channel for immediate electron transfer. Compared to the single-component MoP2 and NiCoP, the synergistic interaction between the heterogeneous components coupling and the 3D porous structure enables MoP2-NiCoP/NF to exhibit satisfactory catalytic activity with an ultralow overpotential of 50 mV at 10 mA cm-2, which is close to the commercial Pt/C catalyst in alkaline media. More importantly, it exhibits good stability, with the ability to be electrolyzed in 1.0 M KOH electrolyte for 24 h without a significant change in overpotential. This study offers directions for the design of low-cost, high-activity, transition metal phosphides (TMPs)-based HER catalyst alternatives for future practical applications.

Facile fabrication of an enhanced electrodeposited nickel electrode for alkaline hydrogen evolution reaction

Electrodeposited nickel (Ni) electrode for alkaline hydrogen evolution reaction (HER) has low cost and high stability advantages, but its catalytic performance is unsatisfactory. In this study, a Ni electrode with a pentagonal pyramid microstructure was first fabricated by electrodeposition, and then the surface microstructure and chemical composition of the electrode were elaborately modified by a simple acid etching treatment which significantly enhanced the HER catalytic performance. The HER over-potential at 10 mA cm−2 on the electrode which was etched for 60 min was reduced from 238 mV to 60 mV compared to the un-etched one. The fabricated electrode could maintain stable catalytic stability at a current density of 100 mA cm−2 beyond 360 h. The surface microstructures and chemical compositions of the electrodes were characterized and the catalytic kinetics were investigated by electrochemical methods. The steps on the pentagonal pyramids on the Ni electrode were preferentially dissolved in the etching treatment and the surface became undulating, which efficiently increased the electrochemically active surface area (ECSA). The etching treatment improved the surface wettability and accelerated the hydrogen bubble detachment speed on the electrode. Meanwhile, the electrode surface was further oxidized in the etching treatment. Metallic Ni and crystal NiO were alternately presented on the electrode surface. The generated NiO could facilitate the Volmer step in the HER, which led to the change of the rate-controlling step from the Volmer step to the Heyrovsky step. Further, the synergistic effect between Ni and NiO with a suitable ratio improved the HER catalytic performance of the electrode.

Defect engineering of 1T′ MX 2 (M = Mo, W and X = S, Se) transition metal dichalcogenide-based electrocatalyst for alkaline hydrogen evolution reaction

The alkaline electrolyzer (AEL) is a promising device for green hydrogen production. However, their energy conversion efficiency is currently limited by the low performance of the electrocatalysts for the hydrogen evolution reaction (HER). As such, the electrocatalyst design for the high-performance HER becomes essential for the advancement of AELs. In this work, we used both hydrogen (H) and hydroxyl (OH) adsorption Gibbs free energy changes as the descriptors to investigate the catalytic HER performance of 1T′ transition metal dichalcogenides (TMDs) in an alkaline solution. Our results reveal that the pristine sulfides showed better alkaline HER performance than their selenide counterparts. However, the activities of all pristine 1T′ TMDs are too low to dissociate water. To improve the performance of these materials, defect engineering techniques were used to design TMD-based electrocatalysts for effective HER activity. Our density functional theory results demonstrate that introducing single S/Se vacancy defects can improve the reactivities of TMD materials. Yet, the desorption of OH becomes the rate-determining step. Doping defective MoS2 with late 3d transition metal (TM) atoms, especially Cu, Ni, and Co, can regulate the reactivity of active sites for optimal OH desorption. As a result, the TM-doped defective 1T′ MoS2 can significantly enhance the alkaline HER performance. These findings highlight the potential of defect engineering technologies for the design of TMD-based alkaline HER electrocatalysts.

Multi-interface engineering of nickel-based electrocatalysts for alkaline hydrogen evolution reaction

High gravimetric energy density and zero carbon emission of hydrogen have motivated hydrogen energy to be an attractive alternative to fossil fuels. Electrochemical water splitting in alkaline medium, driven by green electricity from renewable sources, has been mentioned as a potential solution for sustainable hydrogen production. Hydrogen evolution reaction (HER), as a cathodic half-reaction of water splitting, requires additional overpotential to obtain protons via water adsorption/dissociation, suffering from slow kinetics in alkaline solution. Robust and active nickel (Ni)-based electrocatalyst is a promising candidate for achieving precious-metal comparable performance owing to its platinum-like electronic structures with more efficient electrical power consumption. Various modification strategies have been explored on Ni-based catalysts, among which multi-interface engineering is one of the most effective routines to optimize both the intrinsic activity of Ni-based electrocatalysts and the extrinsic stacked component limitations. Herein, we systematically summarize the recent progress of multi-interface engineering of Ni-based electrocatalysts to improve their alkaline HER catalytic activity. The origin of sluggish alkaline HER kinetics is first discussed. Subsequently, three kinds of interfaces, geometrically and reactively, conductive substrate/electrocatalyst interface, electrocatalyst internal heterointerface, and electrocatalyst/electrolyte interface, were cataloged and discussed on their contribution mechanisms toward alkaline HER. Particular focuses lie on the microstructural and electronic modulation of key intermediates with energetically favorable adsorption/desorption behaviors via rationally designed interfaces. Finally, challenges and perspectives for multi-interface engineering are discussed. We hope that this review will be inspiring and beneficial for the exploration of efficient Ni-based electrocatalysts for alkaline water electrolysis.

Modulating Hydroxyl Adsorption on Transition Metal Nitrides by Magnetic Moments toward Fast Alkaline Hydrogen Evolution

Water dissociation is a critical step limiting the kinetics of electrocatalytic hydrogen evolution reaction (HER) in the alkaline. However, the effect of hydroxyl groups (OH*) on the electrocatalyst surface during the HER process has not been clarified yet. Here, three typical transition metal (TM) nitrides (i.e., Fe2N, Co3N and Ni3N) were investigated by combing theoretical calculation and experiments toward alkaline HER. The results show binding energy of OH* (∆EOH*) and magnetic moment of three nitrides follow the same trend of Fe2N > Co3N > Ni3N, showing a positive correlation. The as-synthesized Ni3N with the smallest magnetic moment shows the best alkaline HER activity due to its lowest water-dissociation barrier and weakest ∆EOH*. Weak adsorption to OH* could promote the fast release of OH* and thus enhance reaction kinetics. A small bond order corresponding to weak interaction between Ni3N and OH* is found to be favorable to the release of OH* and subsequent reaction steps, which originates from the orbital interaction of outer-shell electrons in TM and OH*. This work provides new insights into the design of advanced electrocatalysts using magnetic matrix toward alkaline HER.

An advanced Ru-based alkaline HER electrocatalyst benefiting from Volmer-step promoting 5d and 3d co-catalysts.

In this study, a trimetallic catalyst, NiWRu@NF, is electrodeposited onto nickel foam using chronoamperometry to enhance the hydrogen evolution reaction (HER) in alkaline water electrolysis. The catalyst combines nickel, tungsten, and ruthenium components, strategically designed for efficiency and cost-effectiveness, hydroxyl transfer and water dissociation, and acceleration of hydrogen combination, respectively. Evaluation of NiWRu@NF reveals exceptional performance, with a low overpotential of -50 mV and high current density of -10 mA cm-2, signifying its efficiency in promoting HER. Tafel values further corroborate the catalyst's effectiveness, indicating a rapid reaction rate of hydrogen evolution in such a highly alkaline medium compared to other controls studied along with it. This study underscores the significance of NiWRu@NF in advancing alkaline HER kinetics, paving the way for more efficient electrolysis processes.