Efficient Catalyst For Hydrogen Evolution Reaction Research Articles

Material Engineering Strategies for Efficient Hydrogen Evolution Reaction Catalysts.

Water electrolysis, a key enabler of hydrogen energy production, presents significant potential as a strategy for achieving net-zero emissions. However, the widespread deployment of water electrolysis is currently limited by the high-cost and scarce noble metal electrocatalysts in hydrogen evolution reaction (HER). Given this challenge, design and synthesis of cost-effective and high-performance alternative catalysts have become a research focus, which necessitates insightful understandings of HER fundamentals and material engineering strategies. Distinct from typical reviews that concentrate only on the summary of recent catalyst materials, this review article shifts focus to material engineering strategies for developing efficient HER catalysts. In-depth analysis of key material design approaches for HER catalysts, such as doping, vacancy defect creation, phase engineering, and metal-support engineering, are illustrated along with typical research cases. A special emphasis is placed on designing noble metal-free catalysts with a brief discussion on recent advancements in electrocatalytic water-splitting technology. The article also delves into important descriptors, reliable evaluation parameters and characterization techniques, aiming to link the fundamental mechanisms of HER with its catalytic performance. In conclusion, it explores future trends in HER catalysts by integrating theoretical, experimental and industrial perspectives, while acknowledging the challenges that remain.

Silk derived electrospun carbon nanofibers loaded with CoS nanoparticles as efficient hydrogen evolution reaction catalysts in acidic and alkaline media

The design of a stable and efficient hydrogen evolution catalyst across the entire pH range is of significant importance for the development of hydrogen production technology by electrocatalytic water splitting. This study chose biomass silk fibroin protein as the electrospinning raw material, synthesizing a hybrid membrane of CoS@carbon nanofibers (CNF) with a layered core–shell structure through simple carbonization and hydrothermal treatment. The CoS nanoparticles can grow uniformly and densely on the CNF. By varying the concentrations of hexahydrate cobalt nitrate (Co(NO3)2·6H2O) and thiourea (CH4N2S), the morphology of the synthesized CoS nanoparticles on CNF can be controlled. Different microscopic morphologies lead to differences in the activity of the hydrogen evolution reaction (HER), attributed to variations in the exposed active sites for different morphologies. Compared to pure CNF, the CoS-2@CNF hybrid membrane exhibits excellent HER activity in both acidic and alkaline electrolytes. This highlights the synergistic catalytic effect between CNF and CoS particles. This work provides guidance for the rational design of bio-based catalysts with excellent performance.

Promoted Catalytic Activity of CoSx@MoSx/MoOx Supported on Carbon Papers for Electrocatalytic Hydrogen Evolution Reaction

Developing cost-effective and stable materials for the electrocatalysis of hydrogen evolution reaction (HER) remains challenging. In this study, efficient catalysts for HER were synthesized by integrating the cobalt and molybdenum oxides via electrodeposition, followed by subsequent sulfurization of the as-prepared oxides using chemical vapor deposition (CVD). This methodology allowed the incorporation of both cobalt and molybdenum components into the catalyst in a single step. The as-synthesized CoSx@MoSx/MoOx-based catalysts exhibited excellent hydrogen production performance in acidic media owing to the presence of Co-S and Mo-S bonds in the hybrid structure. Particularly, CoSx@MoSx/MoOx(90@360) and MoSx@CoOx(180@180) displayed the best HER performances with low overpotentials of 80 mV and 150 mV, respectively. The catalysts were highly stable, with their stability preserved for over 1000 cycles with marginal reduction in overall efficiency. Therefore, these findings suggest the potential of CoSx@MoSx/MoOx and MoSx@CoOx composites as ideal candidates for developing low-cost catalysts for electrochemical hydrogen production.

Rationally designing of Co-WS2 catalysts with optimized electronic structure to enhance hydrogen evolution reaction

Designing and developing cost-effective, high-performance catalysts for hydrogen evolution reaction (HER) is crucial for advancing hydrogen production technology. Tungsten-based sulfides (WSx) exhibit great potential as efficient HER catalysts, however, the activity is limited by the larger energy required for water dissociation under alkaline conditions. Herein, we adopt a top-down strategy to construct heterostructure Co-WS2 nanofiber catalysts. The experimental results and theoretical simulations unveil that the work functions-induced built-in electric field at the interface of Co-WS2 catalysts facilitates the electron transfer from Co to WS2, significantly reducing water dissociation energy and optimizing the Gibbs free energy of the entire reaction step for HER. Besides, the self-supported catalysts of Co-WS2 nanoparticles confining 1D nanofibers exhibit an increased number of active sites. As expected, the heterostructure Co-WS2 catalysts exhibit remarkable HER activity with an overpotential of 113 mV to reach 10 mA cm−2 and stability with 30 h catalyzing at 23 mA cm−2. This work can provide an avenue for designing highly efficient catalysts applicable to the field of energy storage and conversion.

Unravelling the role of work function difference on supported Ru nanoclusters for alkaline hydrogen evolution reaction

Fine tuning the work function difference (ΔΦ) between support and Ru which in turn affects the electron distribution of Ru is an effective method for the design of high-performance alkaline hydrogen evolution reaction (HER) catalysts. However, it remains a challenge to understand the intrinsic relationship between HER activity and ΔΦ at the atomic level. Herein, taking N doped graphene supported Ru nanoclusters (Ru/CxNy) as the theoretical model, we demonstrate that the HER activity can be correlated with the variation of ΔΦ. For Ru/C50 with smaller ΔΦ, we find that the Ru atoms located at the top layer of Ru nanoclusters (Ru-t) with lower coordination numbers are the main reaction sites. For Ru/C30N20 with larger ΔΦ, the stronger charge redistributions of Ru is observed, and the electron-deficient Ru atoms closing to the interface (Ru-i) are the main reaction sites with significant improvement HER activity. Our findings demonstrate the role of ΔΦ on Ru/CxNy systems for the alkaline HER, which can provide valuable theoretical guidance for the design of high efficient HER catalysts.

Toward boosted alkaline hydrogen evolution reaction: Covalent organic framework-derived N-doped carbon for highly dispersed cobalt nanoparticles

The preparation of renewable hydrogen via electrocatalytic water splitting is a burgeoning strategy in developing sustainable energy. However, it is still a great challenge to prepare an efficient non-precious metal based electrocatalyst for hydrogen evolution in alkaline electrolysis. Herein, we describe a functional hydrogen evolution reaction (HER) electrocatalyst by the combination of soaking metal ions in covalent organic framework (COF) and high temperature calcination. Especially, the 2Co-NC-700 catalyst possesses large specific surface area, appropriate defective nature and structural distortion, thus it embodies outstanding HER catalytic activity with only an overpotential of 303 mV at the current density of 10 mA cm−2 in the solution of 1.0 M KOH. Moreover, the kinetics and durability are also confirmed. Theoretical calculations not only indicates that the stable configuration combined small-sized cobalt nanoparticles and nitrogen-doped carbon but also reveals the synergistic effect of multiple active sites, while the optimal active location that shows the lowest hydrogen adsorption free energy is a major contributor for excellent HER. This work not only offers a highly efficient HER catalyst in alkaline environment but also provides a novel approach to develop non-precious metal nitrogen-doped carbon materials derived from COF as HER electrocatalysts in alkaline media.

Boosting hydrogen production from alkaline water splitting by regulating interlayer stress via lattice mismatch in NiS/MoS2

Alkaline water splitting currently represents one of the most promising routes for sustainable hydrogen production. However, the key challenge with this method lies in the development of low-cost catalysts showing high-performance for hydrogen evolution reaction (HER). Given the rapid advances in the structural design of HER catalysts, a potential procedure to boost their performance is introduced herein. A controllable interlayer stress is generated at the homojunction NiS/NiS interface of electrodeposited hybrid transition metal sulphide NiS/MoS2, by precisely regulating lattice mismatches of NiS nanostructures, achieve a precise control over its charge transfer resistance and the effective balance of electrochemical area. Accordingly, an optimal design, NM5030 (NiS(50 mA/cm2)-NiS(20 mA/cm2)/MoS2/CC), showing an excellent HER performance in alkaline electrolyte is produced. It can drive a high current density of 10 mA/cm2, 100 mA/cm2 and 400 mA/cm2 at a low overpotential of 18 mV, 93 mV and 161 mV, respectively. Under chronoamperometric test, no obvious reduction in current density is observed after 48 h, indicating its high stability. Overall, this work demonstrates the feasibility and effectiveness of the strategy of fabricating lattice mismatch to find an optimal layered structure based catalyst for efficient HER.

A Cluster-Type Self-Healing Catalyst for Stable Saline–Alkali Water Splitting

In electrocatalytic processes, traditional powder/film electrodes inevitably suffer from damage or deactivation, reducing their catalytic performance and stability. In contrast, self-healing electrocatalysts, through special structural design or composition methods, can automatically repair at the damaged sites, restoring their electrocatalytic activity. Here, guided by Pourbaix diagrams, foam metal was activated by a simple cyclic voltammetry method to synthesize metal clusters dispersion solution (MC/KOH). The metal clusters-modified hydroxylated Ni-Fe oxyhydroxide electrode (MC/NixFeyOOH) by a facile Ni-Fe metal–organic framework-reconstructed strategy, exhibiting superior performance toward the oxygen evolution reaction (OER) in the mixture of MC/KOH and saline–alkali water (MC/KOH+SAW). Specifically, using a nickel clusters-modified hydroxylated Ni-Fe oxyhydroxide electrode (NC/NixFeyOOH) for OER, the NC/NixFeyOOH catalyst has an ultra-low overpotential of 149 mV@10 mA cm−2, and durable stability of 100 h at 500 mA cm−2. By coupling this OER catalyst with an efficient hydrogen evolution reaction catalyst, high activity and durability in overall SAW splitting is exhibited. What is more, benefiting from the excellent fluidity, flexibility, and enhanced catalytic activity effect of the liquid NC, we demonstrate a self-healing electrocatalysis system for OER operated in the flowing NC/(KOH+SAW). This strategy provides innovative solutions for the fields of sustainable energy and environmental protection.

An in situ phase transformation induced mesoporous heterointerface for the alkaline hydrogen evolution reaction.

The phase structure of a catalyst plays a crucial role in determining the catalytic activity. In this study, a facile phosphorization process is employed to achieve the in situ phase transformation from single-phase Co3O4 to CoO/CoP hybrid phases. Characterization techniques, including XRD, BET, SEM, and TEM, confirm the retention of the mesoporous nature during the phase transformation, forming porous CoO/CoP heterointerfaces. Strong charge transfer is observed across the CoO/CoP heterointerface, indicating a robust interaction between the hybrid phases. The CoO/CoP hybrid exhibits significantly enhanced catalytic activity for the alkaline hydrogen evolution reaction (HER) compared to pristine Co3O4. Density Functional Theory (DFT) calculations reveal that the elimination of the band gap in the spin-down band of Co in CoO/CoP contributes to the observed high HER activity. The findings highlight the potential of CoO/CoP hybrids as efficient catalysts for HER, and contribute to the advancement of catalyst design for sustainable energy applications.

Single Ru atoms dispersed on MoSe2/MXene nanosheets with multiple interfaces for enhanced acidic hydrogen evolution

Exposing more catalytic active sites is an effective strategy to enhance the catalyst activity for hydrogen evolution reaction (HER). Herein, Ti3C2Tx MXene served as a substrate to load thin and curved 2H–MoSe2 nanosheets by a typical hydrothermal method, forming MoSe2/MXene heterointerface with the fully exposed Mo edge sites. And then, atomically dispersed Ru single atoms (RuSAs) were successfully anchored on the MoSe2/MXene (RuSAs@MoSe2-MXene). The X-ray absorption near edge structure (XANES) demonstrates that Ru is loaded as single atoms on MoSe2 and MXene. The prepared sample exhibits improved catalytic activity with a small overpotential of 49 mV at 10 mA cm−2 and a low Tafel slope of 52 mV dec−1 for HER in 0.5 M H2SO4. It also exhibits excellent stability with a small attenuation voltage of 10 mV for 120 h at 10 mA cm−2 in 0.5 M H2SO4. When assembled into a two-electrode system of RuSAs@MoSe2-MXene||RuO2, it only requires a relatively low potential of 1.626 V at 10 mA cm−2 to drive overall water splitting (OWS). Control experiments disclose the highly improved performance can be primarily attributed to the introduced RuSAs and MoSe2/MXene heterointerfaces exposing more active sites of Ru and Mo. Moreover, the high conductivity of MXene can increase charge transfer in HER process. The interface engineering with multiple interfaces can provide fresh impetus for the development of efficient HER catalysts.

Directed Dual Charge Pumping Tunes the d-Orbital Configuration of Pt Cluster Boosting Hydrogen Evolution Kinetic.

Achieving high catalytic activity with a minimum amount of platinum (Pt) is crucial for accelerating the cathodic hydrogen evolution reaction (HER) in proton exchange membrane (PEM) water electrolysis, yet it remains a significant challenge. Herein, a directed dual-charge pumping strategy to tune the d-orbital electronic distribution of Pt nanoclusters for efficient HER catalysis is proposed. Theoretical analysis reveals that the ligand effect and electronic metal-support interactions (EMSI) create an effective directional electron transfer channel for the d-orbital electrons of Pt, which in turn optimizes the binding strength to H*, thereby significantly enhancing HER efficiency of the Pt site. Experimentally, this directed dual-charge pumping strategy is validated by elaborating Sb-doped SnO2 (ATO) supported Fe-doped PtSn heterostructure catalysts (Fe-PtSn/ATO). The synthesized 3%Fe-PtSn/ATO catalysts exhibit lower overpotential (requiring only 10.5mV to reach a current density of 10mAcm- 2 ), higher mass activity (28.6 times higher than commercial 20wt.% Pt/C), and stability in the HER process in acidic media. This innovative strategy presents a promising pathway for the development of highly efficient HER catalysts with low Pt loading.

Aluminum-incorporation activates vanadium carbide with electron-rich carbon sites for efficient pH-universal hydrogen evolution reaction

Vanadium carbide (VC) is the greatest potential hydrogen evolution reaction (HER) catalyst because of its platinum-like property and abundant earth reserves. However, it exhibits insufficient catalytic performance due to the unfavorable interaction of reaction intermediates with catalysts. In this work, using NH4VO3 as the main raw material, the flow ratio of CH4 to Ar was accurately controlled, and a non-transition metal Al-doped into VC (100) nano-flowers with carbon hybrids on nickel foams (Al-VC@C/NF) was prepared for the first time as a high-efficiency HER catalyst by chemical vapor carbonization. The overpotential of Al-VC@C/NF catalysts in 0.5 M H2SO4 and 1 M KOH at a current density of 10 mA cm−2 are only 58 mV and 97 mV, respectively, which are the best HER performance among non-noble metal vanadium carbide based catalysts. Simultaneously, Al-VC@C/NF exhibits small Tafel slope (45 mV dec-1 and 73 mV dec-1) and excellent stability in acidic and alkaline media. Theoretical calculations demonstrate that doped Al atoms can induce electron redistribution on the vanadium carbide surface to form electron-rich carbon sites, which significantly reduces the energy barrier during the HER process. This work provides a new tactic to modulate vanadium-based carbons as efficient HER catalysts through non-transition metal doping.

Heterogeneous Cu incorporated into Ni6Fe2-LDH/rGO induces spin exchange interaction to enhance alkaline hydrogen evolution

The efficiency of hydrogen evolution reaction (HER) takes an important influence on electrochemical water electrolysis, yet it still delivers sluggish kinetics mainly due to the high kinetic energy barriers. Herein, Cu1Ni5Fe2-Layered double hydroxides/reduced graphene oxide (denoted as Cu1Ni5Fe2-LDHs/rGO) with heterogeneous Cu atoms incorporated into Ni6Fe2-LDHs/rGO is constructed through a hydrothermal method and doping strategy in this works, wherein the subtle lattice distortion is availably regulated and optimized by Cu2+ Jahn-Teller effect, offering more active sites for HER. As benefits of the subtle lattice distortion and the spin exchange interaction, Cu1Ni5Fe2-LDHs/rGO displays ferromagnetism at room temperature and shows superior alkaline HER properties with a relatively low overpotentials of 50 mV at 10 mA cm−2 in 1.0 M KOH. The low Tafel slope of 38 mV dec−1 implies Cu1Ni5Fe2-LDHs/rGO owns an ultra-fast HER kinetic. This study can offer a new strategy to construct high efficient HER catalysts based on transition metal NiFe-LDHs.

Computational Design of Ni6@Pt1M31 Clusters for Multifunctional Electrocatalysts.

High-efficiency and low-cost multifunctional electrocatalysts for hydrogen evolution reaction (HERs), oxygen evolution reaction (OERs) and oxygen reduction reaction (ORRs) are important for the practical applications of regenerative fuel cells. The activity trends of core-shell Ni6@M32 and Ni6@Pt1M31 (M = Pt, Pd, Cu, Ag, Au) were investigated using the density functional theory (DFT). Rate constant calculations indicated that Ni6@Pt1Ag31 was an efficient HER catalyst. The Volmer-Tafel process was the kinetically favorable reaction pathway for Ni6@Pt1M31. The Volmer-Heyrovsky reaction mechanism was preferred for Ni6@M32. The Pt active site reduced the energy barrier and changed the reaction mechanism. The ORR and OER overpotentials of Ni6@Pt1Ag31 were calculated to be 0.12 and 0.33 V, indicating that Ni6@Pt1Ag31 could be a promising multifunctional electrocatalyst. Ni6@Pt1M31 core-shell clusters present abundant active sites with a moderate adsorption strength for *H, *O, *OH and *OOH. The present study shows that embedding a single Pt atom onto a Ni@M core-shell cluster is a rational strategy for designing an effective multifunctional electrocatalyst.

Graphene-coated cobalt-based coordination polymers for efficient hydrogen evolution reaction catalysts in acidic media

A novel cobalt-based coordination polymer(CP) was synthesised, named [Co(H3L)(bimb)3(H2O)]n, and the complex was compounded with graphene oxide that was calcined at high temperature to form a composite material Co-CP-Go(ω%). Due to the synergistic effect of cobalt-based and graphene, Co-CP-Go(ω%) exhibited good hydrogen precipitation properties in acidic medium. When the content of graphene oxide was 4 %, Co-CP-Go(4 %) showed the best electrocatalytic performance with an over-potential of 115 mV (vs. RHE) at 10 mA cm−2, a Tafel slope of 59 mV dec−1 and good stability in 0.5 M H2SO4 solution. The catalyst is expected to be a good alternative for hydrogen evolution reaction(HER) applications compared to precious metal materials such as platinum-based metals.

Exploring the catalytic properties of Ti2CO2 MXene decorated with Cu-cluster for Hydrogen evolution reaction

Catalysts based on non-noble and cost-effective metals are crucial for the hydrogen evolution reaction (HER) to obtain a viable source of renewable energy in the form of hydrogen. MXene is one of the 2D materials that has recently drawn much interest due to its intriguing catalytic properties. In this work, employing density functional theory we have systematically studied and compared the HER activity of Ti2CO2 MXene with adsorbed Cu3 and Cu5 clusters on top. Our findings suggest that the Ti2CO2 MXene with adsorbed Cu3 cluster exhibits significant enhancement in catalytic activity towards HER. The Gibbs free energy of hydrogen adsorption (ΔGH∗) is found to be −0.08 eV, which is close to the ideal value, suggesting comparable catalytic activity to platinum. In contrast, the Ti2CO2-Cu5 catalyst exhibits a higher Gibbs free energy value of 0.105 eV for HER. The stability of the structures was evaluated by assessing the cohesive and binding energies, supported by Ab Initio Molecular Dynamics (AIMD) simulations. A thorough analysis of the electronic structure and bonding nature of the catalysts are presented. These analyses suggest that the boost in catalytic activity could be ascribed to the accumulated charge at the centre of the Cu3 cluster. Based on our comparison, the Ti2CO2-Cu3 catalyst emerges as a more suitable candidate for the HER process, highlighting its potential as a cost-effective and efficient HER catalyst.

Engineering a synergistic CoMn-LDH/Fe2O3@NF heterostructure for highly efficient oxygen evolution reaction

The pursuit of low-cost, highly efficient energy materials remains a key challenge in clean energy technology. This study introduces a hybrid heterostructure, CoMn-LDH/Fe2O3@NF, comprising Fe2O3 nanosheets coated on CoMn nanowires (NWs) grown on nickel foam (NF). Notably, the heterostructure exhibits exceptional performance in the oxygen evolution reaction (OER), with remarkably low overpotentials (η) of 191 mV and 368 mV, yielding current densities (j) of 10 mA cm−2 and 500 mA cm−2, respectively. Moreover, when coupled with an efficient hydrogen evolution reaction catalyst, CoMn-LDH/Fe2O3@NF achieves j of 10 mA cm−2 and 500 mA cm−2 in overall water splitting at impressively low cell voltages of 1.48 V and 1.82 V, respectively. These exceptional advancements are attributed to the presence of electrochemically accessible active sites, rapid electron transport, and a strong synergistic effect between the Fe2O3 nanosheets and CoMn-LDH NWs. This innovative hybrid heterostructure design holds tremendous potential for advancing next-generation OER catalysts, effectively addressing the demand for cost-effective and highly efficient materials. Significantly, this study contributes to advancing sustainable and viable energy technologies.

Platinum Species on Oxygen Vacancy-Rich Titania for Efficient Basic Electrocatalytic Hydrogen Evolution.

Oxygen vacancy-rich titania is a promising support for enhancing the hydrogen evolution reaction (HER). This work innovatively loaded Pt nanoparticles on oxygen vacancy-rich TiO2 (Pt/Vo-TiO2) in situ by using a photocatalytic device. The synthesis conditions are mild, do not require high temperatures and strong reducing agents, and can avoid the accumulation of platinum species. X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectrometry (XAS) verified the synergistic effect of Pt species and oxygen vacancies on the progress of the reaction kinetics, where the Pt particles exposed by the in situ synthesis functioned as reaction sites in the electrocatalytic hydrogen evolution. Based on this, Pt/Vo-TiO2 exhibits excellent electrocatalytic performance with an overpotential of only 56 mV at a current density of 10 mA cm-2 and a Tafel slope of only 73.5 mV dec-1. This work provides a new strategy for designing highly efficient HER catalysts.

Superhydrophilic/superaerophobic amorphous Ni3S2/NiMoS electrocatalyst for enhanced hydrogen evolution

It is important to develop electrocatalysts that are cheap and have high activity for hydrogen evolution reaction (HER). In this work, Ni3S2/NiMoS with amorphous phase and unique candied-haws shaped nanoarray structure was successfully grown on nickel foam (Ni3S2/NiMoS/NF) as efficient HER catalyst. Combining Ni3S2 with NiMoS resulted in the extension of the heterointerfaces between the materials, which facilitated the HER process in alkaline medium. The amorphous Ni3S2/NiMoS with disordered atom arrangement provided abundant active sites. Also, the unique morphology of the catalytic electrode simultaneously enabled it exhibit superhydrophilicity and underwater superaerophobicity. It is beneficial for the sufficient diffusion of the electrolyte onto the catalyst surface and the fast departure of hydrogen bubbles from the surface. As a result, the activity of Ni3S2/NiMoS/NF was higher than that of Pt/C even at high current densities. It is very valuable for industrial applications that require high current density. The superior stability of Ni3S2/NiMoS/NF compared to Pt/C further demonstrated that this catalytic electrode has potential for industrial applications.

Chemical Vapor Deposition of Ru/RuSe2 Catalyst for Electrolytic Hydrogen Evolution Reaction

AbstractA one‐step synthesis of highly stable Ru/RuSe2 nanoparticles (NPs) on carbon paper is achieved using low temperature and pressure chemical vapor deposition (CVD), resulting in a heterointerface with multiple active sites for catalysis. The catalyst exhibits outstanding performance for the hydrogen evolution reaction (HER) in an alkaline solution, with low overpotentials and fast hydrogen adsorption and desorption kinetics. The Ru/RuSe2/C nanoparticle structure has the potential for large‐scale production and can be used as an efficient catalyst for HER.