Catalysts For Hydrogen Evolution Research Articles

Tailoring Hydrogen Evolution Reaction with single-atom catalysts on Ti[formula omitted]B MBenes: Insights from computational screening

The utilization of single-atom catalysts (SACs) in the context of the Hydrogen Evolution Reaction (HER) holds significant promise for advancing electrocatalysis. Upon implantation or anchoring on two-dimensional (2D) materials, these catalysts exhibit improved stability, selectivity, and reactivity. This study uses density functional theory-based computational techniques to demonstrate the potential of SACs embedded on novel 2D materials, such as MBenes. To assess their HER activity, the transition metals (TMs) are screened as SACs embedded in Ti2B monolayer. Our results indicate that the inclusion of a single TM can finely adjust hydrogen adsorption, resulting in a characteristic volcano-like pattern, and particularly Pd-Ti2B emerges as a standout candidate, with an optimal Gibbs free energy of −0.057 eV. Moreover, Pd-Ti2B exhibits a notable exchange current density of 1.25 × 10−4 Acm−2 surpassing that of numerous traditional metal catalysts, including Pt(111), by approximately 105%. Furthermore, we underscore the electronic characteristics contributing to the extraordinary electrocatalytic activity of a single TM atom encased in Ti2B, viz., Pd-Ti2B, for HER. This study contributes greatly to our understanding of electrocatalytic processes and facilitates the development of potent MBenes-based catalysts for hydrogen evolution.

Ultrahigh Pt-mass-activity catalyst for alkaline hydrogen evolution synthesized by microwave method in air

Platinum (Pt) metal is widely acknowledged as a highly efficient electrocatalyst for hydrogen evolution reaction (HER) in acidic electrolyte. However, its performance in alkaline environments is significantly lower owing to the sluggish water dissociation step. Herein, we synthesized an ultrahigh Pt-mass-activity alkaline HER catalyst using microwave reduction method in air. Our catalyst, PtRu@CNT, comprises PtRu alloy nanoparticles uniformly loaded on carbon nanotubes, with Pt and Ru contents of 12.3 wt% and 4.5 wt%, respectively. The PtRu alloy nanoparticles have an average diameter of about 3 nm and a face-centered cubic structure, and the introduction of Ru has led to a modified electronic structure in Pt. As a result, an impressively low HER overpotential of 13 mV was achieved, significantly lower than commercial 20 wt% Pt/C (61 mV). PtRu@CNT exhibited a high turnover frequency based on metal mass of 3.06 s−1 at 100 mV, about 6 times higher than commercial Pt/C (0.46 s−1 at 100 mV), highlighting its excellent intrinsic activity. The HER mechanism of PtRu@CNT is a Volmer-Tafel mechanism, where the rate-limiting step changed to the recombination of hydrogen atoms from initial water dissociation, attributed to the presence of Ru. The alkaline HER activity of PtRu@CNT ranks among the best of currently reported Pt-based catalysts.

Unsymmetric Co-Facial "Salixpyrrole" Hydrogen Evolution Catalysts: Two Metals are Better than One.

Designing ligand architectures that can mimic enzyme active sites is a promising approach for developing efficient small molecule activation catalysts for sustainable energy applications. Some key design features include chemically distinct binding pockets for multiple metal centers and a three-dimensional structure that controls the positioning of catalytic sites. With these principles in mind, mono- and bimetallic unsymmetric cofacial palladium complexes, 2 and 3, respectively, bearing ligands with calixpyrrole and salen coordination sites, or "salixpyrrole" ligands, are reported. These species were accessed in a straightforward Schiff-base reaction with appreciable yields. In addition, both 2 and 3 were found to be active hydrogen evolution electrocatalysts using para-toluenesulfonic acid monohydrate as the proton source. The two salixpyrrole species displayed different mechanisms of action, with 2 showing a second-order dependence on acid concentration, whereas 3 exhibited a first-order dependence. Moreover, the bimetallic catalyst was significantly more efficient, with higher turnover frequencies, 4640 s-1 vs 1680 s-1 for 2, and lower overpotentials, 0.39 V vs 0.69 V for 2. The results reported herein provide proof-of-concept that bimetallic catalysts with chemically distinct binding sites demonstrate enhanced catalytic properties in comparison to monometallic or symmetric analogues.

Ternary Pentlandites as Hydrogen Evolution Catalysts in Alkaline Media

Ternary Pentlandites as Hydrogen Evolution Catalysts in Alkaline Media

Exploring PtAg onto silanized biogenic silica as an electrocatalyst for H2 evolution: A combined experimental and theoretical investigation

The task of creating a remarkably stable and effective electrochemical catalyst for efficient hydrogen evolution is arduous, primarily due to the multitude of factors that need to be taken into account for the industrial utilization of Pt. In this work, hybrid formation through in-situ reduction of Pt onto biogenic porous silica (Pt-SiO2) is tested for its use as an efficient catalyst for hydrogen production. Exceptionally high electrocatalytic activity and excellent reusability of catalysts up to 200 cycles have been demonstrated. Pt-SiO2 with low Pt content of 0.48 to 0.82 at% with active catalytic sites exhibit superior catalytic activity with a Tafel slope of 22 mV dec−1 and an overpotential of 28 mV (vs. RHE at 10 mA cm−2) as compared to the Pt wire and previously reported bare Pt-SiO2 (0.65 at% and 0.48 at% of Pt), and hybrid (Pt/Ag) structures formed onto two different biogenic porous SiO2 substrates. The best catalytic performance of the Pt1Ag3 cluster, representing a low Pt concentration, has been validated by Density Functional Theory (DFT) calculations. Here, the high production from the Pt1Ag3 cluster is assigned to the mutual synergistic effect between Pt/Ag atoms. The Pt atoms transfer the excess charge to the nearest Ag neighbors inside the cluster, facilitating hydrogen diffusion on the activated sites. These important findings authenticate the superior hydrogen production at reduced Pt concentration on amine-functionalized biogenic porous silica.

Dandelion-like VSe2-embellished CuSe-Co3Se4 hollow nanotube clusters as bifunctional catalysts for high-performance alkaline hydrogen evolution and solar cells

Among the various non-precious metal catalysts that drive hydrogen evolution reactions (HERs) and dye-sensitized solar cells (DSSCs), transition metal selenides (TMSs) stand out due to their unique electronic properties and tunable morphology. Herein, the multicomponent selenide CuSe-Co3Se4@VSe2 was successfully synthesized by doping with metal element vanadium and selenization on the copper-cobalt carbonate hydroxide (CuCo-CH) template. CuSe-Co3Se4@VSe2 exhibited the dandelion-like cluster structure composed of hollow nanotubes doped with VSe2 nanoparticles. Due to the unique structure and the synergistic effect of various elements, CuSe-Co3Se4@VSe2 showed excellent alkaline HER and DSSC performances. The DSSC based on CuSe-Co3Se4@VSe2 exhibited an impressive power conversion efficiency (PCE) of 9.64 %, which was much higher than that of Pt (8.39 %). Besides, it possessed a low HER overpotential of 76 mV@10 mA cm−2 and a small Tafel slope of 88.9 mV dec−1 in 1.0 M KOH.

Modulating the synergy of Pt single atoms and quantum dots on NiFe LDH for efficient and robust hydrogen evolution

Hydrogen evolution reaction (HER) from water electrolysis is an ideal alternative solution to address the energy crisis and develop clean energy. However, the construction of an efficient electrocatalyst with multiple active sites that can ensure high metal utilization and promote reaction kinetics simultaneously still leaves a major challenge. Herein, we present a facile strategy to synthesize a HER catalyst comprising Pt single atoms (PtSA) anchored in Fe vacancies and Pt quantum dots (PtQD) on the surface of NiFe LDH. Benefitting from the hierarchical and ultrathin nanosheet arrays and strong electronic interaction between PtSA/PtQD and NiFe LDH matrix, the optimized sample (PtSA/QD-NiFeV9 LDH) exhibits outstanding HER performance in 1 M KOH with ultra-low overpotentials of 20 and 67 mV at 10 and 100 mA cm-2, respectively, outperforming the benchmark Pt/C electrocatalyst. In addition, the electrolyzer using PtSA/QD-NiFeV9 LDH as a cathode requires voltages of only 1.48 and 1.73 V to yield current densities of 10 and 1000 mA cm-2, respectively. The combination of in situ tests and density functional theory (DFT) calculations reveal that the synergy of PtSA and PtQD can optimize the kinetics of water dissociation and hydrogen desorption, thus the Volmer-Tafel pathway prevailing the HER process. This work provides a promising surface engineering strategy to develop catalysts for efficient and robust hydrogen evolution.

Rational design of porous vanadium-based alloys modified with a Ni-Cu-Mo coating for alkaline water electrolysis

The development of a hydrogen evolution catalyst with both catalytic activity and stability is critical for hydrogen production from electrolytic water. Herein, a V-based porous alloy was prepared via high-energy ball milling and solid-state sintering. Then, the V-based porous alloy was modified with a Ni-Cu-Mo ternary alloy coating by direct current electrodeposition to obtain a composite hydrogen evolution cathode with high hydrogen evolution activity. The substrate has a certain hydrogen storage capacity combined with a high-activity Ni-Cu-Mo coating. The composite hydrogen evolution cathode exhibited high electrocatalytic activity toward the HER. It can afford a lower overpotential of 93 mV and a smaller Tafel slope of 97.4 mV/dec with a current density of 10 mA/cm2 in 1.0 M KOH. The composite hydrogen evolution cathode demonstrated outstanding stability after 2000 cycles and good durability after intermittent electrolysis for 20 hours. Hydrogen protons can protect the components of the cathode composite from dissolution during discontinuous constant potential electrolysis. The composite hydrogen evolution cathode also exhibited a strong catalytic capacity for hydrogen evolution during intermittent electrolysis under alkaline conditions.

Heat-induced aliquation and phosphating of nickel as efficient catalysts for hydrogen evolution in alkaline seawater

Developing electrolytic seawater catalysts with excellent performance is crucial for efficient hydrogen production. In this study, Ni2P nanoparticles anchored on NiMo oxides, denoted as NiMo-P, are synthesized through heat-induced aliquation and phosphating of Ni in the ammonium nickel molybdate. Physicochemical characterizations reveal that the abundant Ni2P nanoparticles are uniformly distributed on NiMo oxides. Electrochemical data reveal that a mere overpotential of 103 mV is sufficient to achieve −100 mA cm−2 in alkaline simulated seawater, which is significantly lower than that of Pt foil (179 mV) and commercial Pt/C (165 mV). This remarkable activity observed in NiMo-P may be due to the superior water dissociation activity and hydrogen desorption ability of the Ni2P nanoparticles, as calculated by density functional theory, which surpasses that of Pt. Meanwhile, the NiMo-P exhibits outstanding stability, as evidenced by the chronoamperometric curve. The current remains at 98.1% of its initial value after 500 h, which can be attributed to the etching-hydrolysis method that strengthens the catalyst-carrier interaction. Besides, the inherent repulsion toward chlorine ions at the cathode effectively avoids chemical corrosion. Importantly, when coupled with the previously reported anode, NiMo-P also exhibits exceptional performance in alkaline seawater.

Ruthenium Nanoclusters and Single Atoms on α-MoC/N-Doped Carbon Achieves Low-Input/Input-Free Hydrogen Evolution via Decoupled/Coupled Hydrazine Oxidation.

The hydrazine oxidation-assisted H2 evolution method promises low-input and input-free hydrogen production. However, developing high-performance catalysts for hydrazine oxidation (HzOR) and hydrogen evolution (HER) is challenging. Here, we introduce a bifunctional electrocatalyst α-MoC/N-C/RuNSA, merging ruthenium (Ru) nanoclusters (NCs) and single atoms (SA) into cubic α-MoC nanoparticles-decorated N-doped carbon (α-MoC/N-C) nanowires, through electrodeposition. The composite showcases exceptional activity for both HzOR and HER, requiring -80 mV and -9 mV respectively to reach 10 mA cm-2. Theoretical and experimental insights confirm the importance of two Ru species for bifunctionality: NCs enhance the conductivity, and its coexistence with SA balances the H ad/desorption for HER and facilitates the initial dehydrogenation during the HzOR. In the overall hydrazine splitting (OHzS) system, α-MoC/N-C/RuNSA excels as both anode and cathode materials, achieving 10 mA cm-2 at just 64 mV. The zinc hydrazine (Zn-Hz) battery assembled with α-MoC/N-C/RuNSA cathode and Zn foil anode can exhibit 97.3 % energy efficiency, as well as temporary separation of hydrogen gas during the discharge process. Therefore, integrating Zn-Hz with OHzS system enables self-powered H2 evolution, even in hydrazine sewage. Overall, the amalgamation of NCs with SA achieves diverse catalytic activities for yielding multifold hydrogen gas through advanced cell-integrated-electrolyzer system.

Amorphous MoS2 from a machine learning inter-atomic potential.

Amorphous molybdenum disulfide has shown potential as a hydrogen evolution catalyst, but the origin of its high activity is unclear, as is its atomic structure. Here, we have developed a classical inter-atomic potential using the charge equilibration neural network method, and we have employed it to generate atomic models of amorphous MoS2 by melting and quenching processes. The amorphous phase contains an abundance of molybdenum and sulfur atoms in low coordination. Besides the 6-coordinated molybdenum typical of the crystalline phases, a substantial fraction displays coordinations 4 and 5. The amorphous phase is also characterized by the appearance of direct S-S bonds. Density functional theory shows that the amorphous phase is metallic, with a considerable contribution of the 4-coordinated molybdenum to the density of states at the Fermi level. S-S bonds are related to the reduction of sulfur, with the excess electrons spread over several molybdenum atoms. Moreover, S-S bond formation is associated with a distinctive broadening of the 3s states, which could be exploited for experimental characterization of the amorphous phases. The large variety of local environments and the high density of electronic states at the Fermi level may play a positive role in increasing the electrocatalytic activity of this compound.

Tungsten(VI) oxide-supported nickel/silver nanoparticles for photocatalytic hydrogen evolution from ammonia-borane

Developing efficient catalysts for hydrogen (H2) evolution from ammonia-borane (AB, NH3BH3) is crucial for fuel cell applications. Photocatalytic hydrolysis of AB by heterogeneous catalysts under light irradiation has attracted attention as an effective technique for H2 evolution. Here, we report an impregnation-reduction method to prepare the tungsten(VI) oxide-supported nickel/silver nanoparticles (denoted as NiAg/WO3) and their characterization by advanced tools such as ICP-OES, PXRD, SEM, TEM, and XPS. The initial turnover frequency (TOF), activation energy (Ea#), activation enthalpy (ΔH#), and activation entropy (ΔS#) values of NiAg/WO3 nanoparticles in H2 evolution from AB under visible light irradiation are calculated as 56.6 molH2 ⋅ molNi0.27Ag0.73−1 ⋅ min−1, 52.14 kJ ⋅ mol−1, 47.78 kJ ⋅ mol−1, and −91.62 J ⋅ mol−1 ⋅ K−1, respectively. These findings are especially significant for a feasible application of AB in H2 fuel cells.

Atmospheric oxygen plasma-activated novel multicomponent transition metal phosphides (MnCoCu–P) for enhanced electrocatalytic water splitting to green hydrogen production: A universal catalyst across various pH electrolytes

Hydrogen (H2) is widely acknowledged as a promising, sustainable, and environmentally friendly energy carrier, offering numerous environmental benefits over conventional fossil fuels. However, the advancement of this technology is severely hindered by the scarcity of effective and robust catalysts for hydrogen evolution (HER) and oxygen evolution (OER) reactions activity. This study marks the inaugural fabrication of a hybrid tri-metallic electrocatalyst, termed MnCoCu–P, through hydrothermal synthesis. Subsequently, the catalyst undergoes atmospheric O2 plasma surface activation, aiming to amplify the efficiency of water splitting. The novel atmospheric O2 plasma-activated MnCoCu–P electrode outperforms the reported classic metal phosphides, and it outperformed the compared commercial Pt/C and RuO2 benchmark catalysts with outstanding performances of 0.488 and 1.20 V towards HER and OER at 1000 mA/cm2, respectively. Additionally, the MnCoCu–P (5 min) catalyst Faradic efficiency was calculated under alkaline conditions in 1.0 M KOH, and both the produced gas H2 and O2 match the theoretical and experimental calculated values well, indicating a high efficiency of almost 100%. In the 2-E system, MnCoCu–P (5 min)‖MnCoCu–P (5 min) demonstrated remarkable performance by attaining a current density of 1000 mA/cm2 at low total cell voltages of 1.93 V and outperforming the benchmark Pt/C‖RuO2 electrode system. On the other hand, the MnCoCu–P electrode possesses excellent activity under industrial conditions at 6.0 M @ 60 °C exhibited 1.89 V at 1000 mA/cm2 and performs well in natural water systems. Moreover, the 5 min O2 plasma-treated MnCoCu–P‖MnCoCu–P electrodes showed improved activity in all the pH solutions which makes it one of the potential candidates for commercial application in the future.

Efficient hydrogen evolution activity of NiMoP electrodeposited on stainless steel mesh

In the context of industrial water electrolysis cells, the electrocatalyst often exhibits slow kinetics in water dissociation, allowing for reduced electrocatalytic performance in the production of hydrogen through water splitting. This report presents a novel ternary Nickel–Molybdenum–Phosphide (NiMoP) catalyst synthesis as a quick Tafel-step-decided electrocatalyst toward hydrogen evolution reaction (HER). Herein, we systematically evaluate the performance of various nickel-based catalysts when electrodeposited over the stainless-steel mesh (SSM) substrate for water electrolysis. The results reveal a diminishing trend in both the Tafel slope and overpotential in relation to the catalyst composition, following the order of Ni > NiMo > NiP > NiMoP. Consequently, NiMoP/SSM emerges as the top performer, displaying outstanding performance in terms of thermodynamics (the current density of 10 mA cm−2, η10 = 239 mV) and kinetics (STafel = 98.22 mV·dec⁻¹ at 1.0 M KOH) in water splitting. Thus, this novel ternary NiMoP catalyst with SSM, prepared through a straightforward and cost-effective synthesis method, holds great promise as a non-precious hydrogen evolution catalyst in water electrolyzing.

Nickel Nanoparticles Supported on P-Doped Tungsten Nitride Nanosheets as Catalysts for Hydrogen Evolution

Nickel Nanoparticles Supported on P-Doped Tungsten Nitride Nanosheets as Catalysts for Hydrogen Evolution

Integration of biocompatible hydrogen evolution catalyst developed from metal-mix solutions with microbial electrosynthesis

Microbial conversion of CO2 to multi-carbon compounds such as acetate and butyrate is a promising valorisation technique. For those reactions, the electrochemical supply of hydrogen to the biocatalyst is a viable approach. Earlier we have shown that trace metals from microbial growth media spontaneously form in situ electro-catalysts for hydrogen evolution. Here, we show biocompatibility with the successful integration of such metal mix-based HER catalyst for immediate start-up of microbial acetogenesis (CO2 to acetate). Also, n-butyrate formation started fast (after twenty days). Hydrogen was always produced in excess, although productivity decreased over the 36 to 50 days, possibly due to metal leaching from the cathode. The HER catalyst boosted microbial productivity in a two-step microbial community bioprocess: acetogenesis by a BRH-c20a strain and acetate elongation to n-butyrate by Clostridium sensu stricto 12 (related) species. These findings provide new routes to integrate electro-catalysts and micro-organisms showing respectively bio and electrochemical compatibility.

Review—Self-Supporting Electrocatalysts for HER in Alkaline Water Electrolysis

Hydrogen is a prime candidate for replacing fossil fuels. Electrolyzing water to produce hydrogen stands out as a particularly clean method, garnering significant attention from researchers in recent years. Among the various techniques for electrolyzing water to produce hydrogen, alkaline electrolysis holds the most promise for large-scale industrialization. The key to advancing this technology lies in the development of durable and cost-effective electrocatalysts for the hydrogen evolution reaction (HER). Self-supporting electrode is an electrode structure in which a catalyst layer is formed directly on a substrate (such as carbon cloth, nickel foam, stainless steel, etc) without using a binder and with good structural stability. In contrast to traditional nanocatalysts, self-supporting electrocatalysts offer significant advantages, including reduced resistance, enhanced stability, and prolonged usability under high currents. This paper reviews recent advancements in HER electrochemical catalysts for alkaline water electrolysis, focusing on the utilization of hydrogen-evolving catalysts such as metal sulfides, phosphides, selenides, oxides, and hydroxides. With self-supported electrocatalysts as the focal point, the paper delves into progress made in their preparation techniques, structural design, understanding of reaction mechanisms, and strategies for performance enhancement. Ultimately, the future development direction of promoting hydrogen evolution by self-supported electrocatalysts in alkaline water electrolysis is summarized.

Theoretical study of electrochemical hydrogen evolution reaction of Pt–Co diatomic sites catalyst

Hydrolytic Hydrogen is a clean hydrogen production method. To mitigate the substantial costs associated with water electrolysis, electrocatalysts are crucial in decreasing the cathodic reaction involved in hydrogen hydrolysis, specifically, the overpotential for hydrogen evolution reaction (HER). Compared to traditional catalysts and single-atom catalysts, Pt–Co diatomic sites catalyst exhibit excellent hydrogen evolution reaction activity and stability. We have established eight different structures of dual-center metal catalysts based on graphene planes. A systematic study was conducted on the catalytic performance and mechanism of these configurations, among which the structure with the best hydrogen evolution reaction activity was CoN4/PtC2N2, with a Gibbs free energy (ΔG) of 0.004 eV. Electronic structure analysis confirms that H follows the Sabatier mechanism on diatomic catalysts, and the catalyst exhibits excellent HER performance for moderate adsorption strength of H atoms. The d-band centers of Co and Pt atoms in the electrocatalyst CoN4–PtC2N2 are lower than those of a single system, indicating that the electronic effect between the CoN4 and PtC2N2 sites can enhance the inherent HER activity of the catalyst. This study expands the application scope of dual-site catalysts and provides new insights for the design and synthesis of dual-site hydrogen evolution catalysts.

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.

Construction of P-doped high efficiency hydrogen evolution catalyst

Transition metal hydrogen evolution catalysts have attracted much attention. Here, we prepared a high-efficiency HER electrocatalyst based on nickel foam by constant current electrodeposition. Based on Mo and Co elements, the ternary catalyst was prepared by adding P, and the synthesized CoMoP-NF catalyst showed a remarkable effect in alkaline electrolytes. The overpotential of the CoMoP-NF catalyst is 35.1 mV at a current density of −10 mA cm−2 and 71 mV at −20 mA cm−2. The composition and structure of the catalyst were studied by SEM, XRD, XPS and TEM. And the stability of the CoMoP-NF catalyst with the best catalytic performance was tested for 12 hours, there is only a tiny increase in overpotential, indicating that the catalyst had excellent stability. This work has a certain impact on the preparation of efficient hydrogen evolution catalyst.