Hydrogen Evolution Reaction Catalysts Research Articles

Molybdenum sulfide modified with nickel or platinum nanoparticles as an effective catalyst for hydrogen evolution reaction

In this study, we investigate the catalytic performance of molybdenum sulfide (MoS2) modified with either nickel (Ni) or platinum (Pt) nanoparticles as catalysts for the hydrogen evolution reaction (HER). The MoS2 was prepared on the TiO2 nanotube substrates via a facile hydrothermal method, followed by the deposition by magnetron sputtering of Ni or Pt nanoparticles on the MoS2 surface. Structural and morphological characterization confirmed the successful incorporation of Ni or Pt nanoparticles onto the MoS2 support. Electrochemical measurements revealed that Ni- and Pt-modified MoS2 catalysts exhibited enhanced HER activity compared to pristine MoS2. Obtained catalysts demonstrated a low onset potential, reduced overpotential, and increased current density, indicating efficient electrocatalytic performance. Furthermore, the Ni or Pt-modified MoS2 catalyst exhibited remarkable stability during prolonged HER operation. The improved catalytic activity can be attributed to the synergistic effect between metal nanoparticles and MoS2, facilitating charge transfer kinetics and promoting hydrogen adsorption and desorption. Incorporating Ni and Pt nanoparticles also provided additional active sites on the MoS2 surface, enhancing the catalytic activity.

Ruthenium-Based Electrocatalysts for Hydrogen Evolution Reaction: from Nanoparticles to Single Atoms.

Benefiting from similar hydrogen bonding energy to Pt and much lower price compare with Pt, Ru based catalysts are promising candidates for electrocatalytic hydrogen evolution reaction (HER). The catalytic activity of Ru nanoparticles can be enhanced through improving their dispersion by using different supports, and the strong metal supports interaction can further regulate their catalytic performance. In addition, single-atom catalysts (SACs) with almost 100% atomic utilization attract great attention and the coordinative atmosphere of single atoms can be adjusted by supports. Moreover, the syngenetic effects of nanoparticles and single atoms can further improve the catalytic performance of Ru based catalysts. In this review, the progress of Ru based HER electrocatalysts are summarized according to their existing forms, including nanoparticles (NPs), single atoms (SAs) and the combination of both NPs and SAs. The common supports such as carbon materials, metal oxides, metal phosphides and metal sulfides are classified to clarify the metal supports interaction and coordinative atmosphere of Ru active centers. Especially, the possible catalytic mechanisms and the reasons for the improved catalytic performance are discussed from both experimental results and theoretical calculations. Finally, some challenges and opportunities are prospected to facilitate the development of Ru based catalysts for HER.

Synthesis of binder-free hybrid Ni-Co-Se@NiS2 nanostructures as highly active and durable electrocatalyst for hydrogen evolution reaction in alkaline media and Seawater

The Ni-Co-Se structures have been widely examined as an electrocatalyst for the hydrogen evolution reaction (HER). Despite the excellent electrical transportability, they suffer from low profusion of active electrocatalytic sites as well as poor long-term durability. Herein, we demonstrated Nickel-Disulfur doping in Ni-Co-Se as an effective method to simultaneously elevate electrocatalytic activity and stability. In this study, the preparation and optimization of the Ni-Co-Se@NiS2 core–shell structure were discussed using hydrothermal and electrodeposition processes. The electrocatalytic activity of the synthesized samples was investigated in both 1 M KOH solution and Seawater. The results of the electrochemical and microstructural investigations showed that the electrodeposition of NiS2 on Ni-Co-Se under the condition of pulsed potential with a frequency of 0.01 Hz by creating a dual micro-nanometric structure with a high edge area, needed only 73 and 81 mV of overpotentials to achieve a current density of 10 mA.cm2 in KOH and Seawater, respectively, as well as continuous stable operation over 30 h. The excellent kinetics with only 1.7 Ω.cm2 charge transfer resistance reached 300 mV overpotential, the high electrochemically active surface area (ECSA) equal to 1900 cm2, and a turnover frequency (TOF) value of 0.160 s−1 at 140 mV indicate the promising electrocatalytic HER performance of the Ni-Co-Se@NiS2 catalyst. This work introduced a novel strategy for the design and synthesis of high-level selenide-based HER catalysts.

Homoleptic nickel(II)-dithiocarbamates as potent homogeneous electrocatalysts for hydrogen evolution reaction: Effect of positional isomeric –OH group on electrocatalytic properties

Three positional isomeric homoleptic Ni(II) dithiocarbamate complexes having general formula [Ni(L)2] (L=N-benzyl-1-(2-hydroxyphenyl) dithiocarbamate (Ni-1); N-benzyl-1-(3-hydroxyphenyl) dithiocarbamate (Ni-2) and N-benzyl-1-(4-hydroxyphenyl) dithiocarbamate (Ni-3)) have been synthesized and characterized by elemental analysis, FT-IR, UV–Vis., multinuclear NMR spectroscopy and single crystal X-ray diffraction. The single crystal X-ray analysis for Ni-2 reveals distorted square planar geometry around Ni(II), that is satisfied by four sulfur centers of two N-benzyl-1-(3-hydroxyphenyl) dithiocarbamate ligands. The nature of weak interactions in Ni-2 have been explored using Hirshfeld surface analysis, which suggest that the percentage contribution of O···H interactions is more than S···H interactions. These complexes have been employed as homogeneous catalysts for electrochemical hydrogen evolution reaction suggesting turnover frequency (TOF) of 566.2, 457.2 and 867.9 s−1 for Ni-1, Ni-2 and Ni-3, respectively on adding 30 mM trifluoroacetic acid (TFA). Also, the overpotential (η) values for Ni-1, Ni-2 and Ni-3 are 0.862, 0.872 and 0.723 V, respectively. The variation in the electrocatalytic properties was explained on the basis of theoretical calculations which suggested that the para-OH isomer complex possess relatively larger HOMO-LUMO energy gap, compared to ortho-OH and meta-OH isomeric complexes and indicated the relative less stable nature of para-OH isomer complex and its better susceptibility towards electrons at a lower negative potential.

Amorphous W-doped iron phosphide with superhydrophilic surface to boost water-splitting under large current density

Electrochemical water-splitting is an effective approach for producing hydrogen without producing any pollutants, but its large-scale development is hampered by the lack of low-cost and efficient electrocatalysts. Therefore, it is essential to explore efficient and low-cost non-precious catalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Herein, W-doped Fe-P/IF amorphous nanoflake arrays (W-Fe-P/IF) are synthesized by corrosive avenue and following low-temperature phosphorization. Benefiting from the superhydrophilic surface, amorphous structure, nanosheet morphology and abundant active sites, the synthesized catalysts exhibited good catalytic performance. Therefore, the W-Fe-P/IF electrocatalyst onws low overpotentials of 35, 67, and 105 mV to achieve 10 mA cm−2 in 1 M KOH, 1 M KOH + seawater, and 1 M PBS, respectively. In addition, it also exhibits low voltage of 1.63 V to obtain 10 mA cm−2 coupled with excellent stability under 500 mA cm−2. The work provides a new strategy for the preparation of highly-efficient and low-cost non-precious electrocatalysts on renewable energy-related applications.

Preparation of sugarcane bagasse carbon-coated molybdenum phosphide nanocomposite electrocatalyst for hydrogen evolution reaction

The hydrogen evolution reaction (HER) based on electrochemical water decomposition is a promising method for producing clean and sustainable hydrogen energy. However, it is necessary to find high-activity, inexpensive, and durable non-precious metal-based electrocatalysts to realize HER. In this study, we prepared sugarcane bagasse carbon (SCBC) coated molybdenum phosphide nanocatalyst (MoP/SCBC) using a simple method and investigated the HER of the catalyst in acidic media. The MoP nanoparticles were uniformly coated on SCBC to form a unique structure, resulting in excellent electrocatalytic activity and stability of the MoP/SCBC catalyst in 0.5 M H2SO4 solution. The overpotential of the MoP/SCBC-900 catalyst was as low as 126 mV at 10 mA cm−2. The Tafel slope was 60.6 mV dec−1, and the Cdl was 18.83 mF cm−2, which outperformed most reported MoP-based HER catalysts. This study provides a more effective approach for developing high performance MoP based non-precious metal electrocatalysts derived from low-cost biomass.

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.

Modulating the reduction potential and ligand basicity of Ni(II) HER catalysts with highly conjugated N2S2 ligands

Molecular catalysts with N2S2 chelates and earth abundant metals have been used in different applications. With their versatile nature to modulate activity through changes in the ligand framework, they are excellent candidates to generate low-cost and sustainable energy as electrocatalysts for the hydrogen evolution reaction (HER). Herein we demonstrate the modulation of the reduction potential and basicity across a series of six square planar Ni(II) complexes with bis(thiosemicarbazonato) (BTSC), hybrid thiosemicarbazonato-alkylthiocarbamato (TSTC), and bis(alkylthiocarbamato) (BATC) ligands and evaluate their activity as homogenous HER catalysts. The redox active ligands have been designed to modulate the electronic structure of the N2S2Ni core and to systematically alter their respective pKa values. Cyclic voltammograms of all six complexes show two reversible reduction events in acetonitrile that systematically shift to more anodic potentials when the pendent methylthiosemicarbazonato (–NN=C(S)NHMe) groups are substituted with ethylthiocarbamato (–NN=C(S)OEt) groups and/or when the 2,4-butanedione backbone is replaced by 1-phenyl-1,2-propandione. Ligand basicity was evaluated by spectroscopic titration in acetonitrile and found to vary systematically across the series. Within the series of complexes the reduction potentials vary over an ∼ 500 mV range and the ligand basicity over ∼ 7 pKa units. Density functional theory (DFT) computations are consistent with experimental changes in redox potential and pKa values across the series of complexes. The results demonstrate a unique example in which electronic properties of the complexes are modulated via small ligand structure variations. The complexes are stable under acidic conditions or upon reduction, but they degrade upon reduction in the presence of acid limiting their application as homogeneous HER electrocatalysts.

Titanium dioxide heterojunction support design induced robust platinum catalytic hydrogen evolution over wide pH range

The development of efficient hydrogen evolution reaction (HER) electrocatalysts is critical for water splitting. Herein, rutile/anatase titanium dioxide heterojunction supported platinum nanoparticles (Pt-NPs) design with interfacial effect was developed as efficient HER catalyst (Pt@R/A-TiO2) over wide pH range. The R/A-TiO2 support design induces aggregated Pt-NPs on the heterojunction interface. In-situ Raman and in-situ infrared investigations over wide pH range reveal that there exists a strong hydrogen spillover from Pt-NPs to R/A-TiO2 support and fast proton transfer HER kinetics on Pt@R/A-TiO2. Theoretical calculations demonstrate that the R/A-TiO2 heterojunction modulates more electrons transferred from TiO2 support to Pt-NPs, and this electron-rich Pt-NPs weakens H adsorption, thus enhancing the hydrogen spillover effect and improving the HER performance of Pt@R/A-TiO2. In acidic/alkaline/neutral media, Pt@R/A-TiO2 demonstrates excellent HER activity and stability. Especially in acidic media, Pt@R/A-TiO2 exhibits high mass activity of 12.57 A mgPt−1 at an overpotential of 100 mV, which is nearly 11 times higher than Pt/C, and outperforms the recently reported Pt-based catalysts as well. This work advances the design of efficient and stable HER catalysts over wide pH range.

Synthesis of MS2 (M=Mo, W) thin films by chemical solution deposition

MoS2 and WS2 as typical two-dimensional transition metal dichalcogenides have been investigated since of rich physicochemical properties. To deposit MoS2 and WS2 thin films, chemical solution deposition as a facile route had been used showing the advantages of high component controllability, low cost, sequential processing of device, easy preparation of large-size films and facile preparation of films on irregular substrates. Here, Mo1-xWxS2 (0 ≤ x ≤ 1) thin films were successfully prepared by chemical solution deposition method. The phases as well as microstructures were investigated using field emission scanning electron microscope, atomic force microscopy, transmission electron microscopy, Raman and x-ray photoelectron spectroscopy measurements. The prepared Mo1-xWxS2 thin films are used as hydrogen evolution reaction (HER) catalyst electrodes for water splitting. The Mo0·3W0·7S2 thin film catalyst shows an overpotential of 345 mV at a current density of 10 mA cm−2 and the corresponding Tafel slope of 169 mV dec−1 in 0.5 M sulfuric acid. The results will provide a facile method to deposit MX2 thin films.

Spatially confined synthesis of large-sized MoS2 nanosheets in molten KSCN toward efficient hydrogen evolution

Low-temperature KSCN molten salt is a promising technique to synthesize defect-rich MoS2 catalysts for hydrogen evolution reaction (HER). However, owing to the fast ion diffusion rate for rapid crystal growth, the resultant catalysts show a morphology of microsphere, which aggregates from MoS2 nanosheets, to suppress the catalytic performance. In this work, large-sized few-layer MoS2 nanosheets are synthesized via a spatial confinement strategy by adding inert NaCl into the KSCN molten salt. With the NaCl spacer to physically block the long-distance ion diffusion and isolate the chemical reaction, the MoS2 nucleation and subsequent crystal growth could be controlled, guiding the nanosheets to grow along the narrow gap between the NaCl crystals to avoid aggregation. As a result, ultrathin MoS2 nanosheets with a large geometry size are constructed. Profiting from the architecture to expose active sites and boost charge transfer kinetics, the large-sized few-layer MoS2 nanosheets exhibit an impressive HER performance, showing a small η 10 of 160 mV and a low Tafel slope of 53 mV dec−1 with excellent stability. This work provides not only an efficient HER catalyst but also a facile spatial confinement technique to design and synthesize a large spectrum of transition metal sulfides for broad uses.

Assembling 2D Ni‐Co nanosheets onto Mo2C Nanorod towards Efficient Electrocatalytic Hydrogen Evolution†

Comprehensive SummaryA novel electrocatalyst, Ni‐Co/β‐Mo2C@C, was rationally designed to enhance the efficiency of the hydrogen evolution reaction (HER) in this work. Assembled with two‐dimensional Ni‐Co nanosheets onto Mo2C nanorods coated with a thin carbon shell, the catalyst demonstrates remarkable performance, including low overpotential (η10 = 57 mV) and reduced Tafel slope (63 mV·dec–1) in 0.5 mol·L–1 H2SO4 electrolyte. This innovative design strategy provides abundant active sites and efficient electron/ion transport pathways, effectively shortening reactant diffusion distances and enhancing electrocatalytic activity. Additionally, the carbon shell coating protects the catalyst from etching and agglomeration, ensuring its durability. This work presents a promising approach for engineering highly efficient metal carbide‐based HER catalysts through tailored composition and nanostructure design.

Phase-controlled synthesis of starch-derived Mo2C–MoC/C heterostructure catalyst for electrocatalytic hydrogen evolution reaction

The electronic structure of molybdenum carbide closely resembles that of Pt, making it a promising candidate material for replacing noble metal catalysts. However, the primary challenge is the controlled and eco-friendly synthesis of molybdenum carbide. Herein, we developed a sustainable and controlled method for synthesizing a heterostructure catalyst for the electrocatalytic hydrogen evolution reaction (HER) using starch as the raw material. Through a hydrothermal redox reaction and subsequent temperature-programmed treatment under an inert atmosphere, the hexagonal Mo2C-cubic MoC heterostructure nanoparticles were dispersed on a carbon matrix. Our investigation into the synthesis process extensively covered the growth of MoO2 nanocrystals and hydrochar during the hydrothermal redox reaction, as well as the phase evolution during the subsequent temperature-programmed treatment. Electrochemical assessments demonstrated the catalyst's remarkable efficiency for the hydrogen evolution reaction across both acidic and alkaline media, achieving a current density of 10 mA/cm2 with an overpotential of 139.4 mV in 1 M KOH solution and 160.7 mV in 0.5 M H2SO4 solution. Combining a series of electrochemical characterizations and applying the distribution of relaxation times (DRT) analysis to operando electrochemical impedance spectroscopy (EIS) data, the superior kinetic performance of the Mo2C–MoC/C was demonstrated, outperforming that of single-phase molybdenum carbide. Furthermore, the catalyst has demonstrated remarkable stability even at high current densities in both acidic and alkaline electrolytes, underscoring its potential as a cathode catalyst in both alkaline water electrolyzers and proton exchange membrane (PEM) electrolyzers.

Layered -bismuthene maximizes the active sites in Bi2Te3 towards electrocatalytic hydrogen evolution reactions

The need of sustainable energy sources drives the development of efficient hydrogen evolution reaction (HER) catalysts, inspiring innovative approaches to boost catalytic performance. Here, we introduce a method harnessing the unique properties of layered bismuthene to enhance the active sites of Bi2Te3. Through comprehensive characterization using XRD, FTIR, SEM, TEM, XPS, and Raman analysis, we elucidate the structural and morphological features of the synthesized material. Electrochemical assessments by employing cyclic voltammetry, linear sweep voltammetry, electrochemical impedance spectroscopy, and chronoamperometry techniques reveal the superior electrocatalytic performance of bismuthene incorporated Bi2Te3 composite, characterized by reduced overpotential (119 mV vs RHE at −10 mA/cm2) and Tafel slope (95.4 mV/dec). These findings underscore the efficacy of a few layered bismuthene in enhancing hydrogen production activity, particularly in alkaline environments, for sustainable water splitting processes. Our work presents findings that contribute to the development of catalysts which are scalable, eco-friendly and promise to revolutionize renewable energy technologies, paving the way for a cleaner and more accessible era of hydrogen fuel.

Europium Oxide Evoked Multisite Synergism to Facilitate Water Dissociation for Alkaline Hydrogen Evolution

AbstractExploring an efficient nonnoble metal catalyst for hydrogen evolution reaction (HER) is critical for industrial alkaline water electrolysis. However, it remains a great challenge due to the additional energy required for H─OH bond cleavage and the lack of enough H2O adsorption sites for most catalysts. Herein, the integration of oxophilic Eu2O3 with NiCo alloy with evoked multisite synergism to facilitate water dissociation for alkaline HER is proposed. The optimized Eu2O3‐NiCo exhibits excellent HER activity with a low overpotential of only 60 mV at 10 mA cm−2 and good electrochemical stability, which is superior to that of Eu2O3‐free NiCo and comparable to benchmark Pt/C. The key roles of Eu2O3 on the enhanced HER performance of Eu2O3‐NiCo are identified by in situ Raman spectroscopy and theoretical calculations. It is discovered that the Eu2O3 with strong oxophilicity facilitates the adsorption of H2O and the breakage of H─OH bonding while evoking the electron redistribution at Eu2O3/NiCo interface and accelerating the Volmer step in alkaline HER. Furthermore, the obtained Eu2O3‐NiCo as both anode and cathode displays excellent overall water‐splitting activity and stability in 1.0 M KOH solution. It is believed that this study provides an important inspiration to design high‐performance electrocatalysts toward HER based on rare‐earth materials.

Solvent-free synthesis of nickel doped ruthenium for efficient hydrogen evolution

The efficient transformation of chemicals and electricity via electrocatalytic hydrogen evolution reaction (HER) plays a pivotal role in green hydrogen production. Both in academia and industry, the pursuit of designing and fabricating catalysts for HER that are not only efficient and robust but also environmentally friendly is of significant interest. In this work, a ruthenium catalyst doped with nickel was synthesized using a procedure-minimal and solvent-free method facilitated by microwave-assisted pyrolysis. The incorporation of alloying and optimized electronic structures has resulted in Ru-based nanocrystals that change the HER mechanism and enable enhanced activity. The optimal RuNi/C catalyst demonstrates an overpotential of only 15 mV at a current density of 10 mA cm−2, with a Tafel slope of 24 mV dec−1, surpassing the performance of the state-of-the-art Pt/C catalyst. Remarkably, the prepared catalyst exhibits admirable corrosion resistance, making it a highly promising candidate for green hydrogen production through seawater splitting.

Catalytic Water Electrolysis by Co-Cu-W Mixed Metal Oxides: Insights from X-ray Absorption Spectroelectrochemistry.

Mixed metal oxides (MMOs) are a promising class of electrocatalysts for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Despite their importance for sustainable energy schemes, our understanding of relevant reaction pathways, catalytically active sites, and synergistic effects is rather limited. Here, we applied synchrotron-based X-ray absorption spectroscopy (XAS) to explore the evolution of the amorphous Co-Cu-W MMO electrocatalyst, shown previously to be an efficient bifunctional OER and HER catalyst for water splitting. Ex situ XAS measurements provided structural environments and the oxidation state of the metals involved, revealing Co2+ (octahedral), Cu+/2+ (tetrahedral/square-planar), and W6+ (octahedral) centers. Operando XAS investigations, including X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS), elucidated the dynamic structural transformations of Co, Cu, and W metal centers during the OER and HER. The experimental results indicate that Co3+ and Cu0 are the active catalytic sites involved in the OER and HER, respectively, while Cu2+ and W6+ play crucial roles as structure stabilizers, suggesting strong synergistic interactions within the Co-Cu-W MMO system. These results, combined with the Tafel slope analysis, revealed that the bottleneck intermediate during the OER is Co3+ hydroperoxide, whose formation is accompanied by changes in the Cu-O bond lengths, pointing to a possible synergistic effect between Co and Cu ions. Our study reveals important structural effects taking place during MMO-driven OER/HER electrocatalysis and provides essential experimental insights into the complex catalytic mechanism of emerging noble-metal-free MMO electrocatalysts for full water splitting.

Ring-shaped cavity anchor Pt to derive Pt/WO3-x heterointerfaces for efficient hydrogen evolution in acidic water and seawater

Developing novelplatinum (Pt)-based hydrogen evolution reaction (HER) catalysts with high activity and stability is significant for the ever-broader applications of hydrogen energy. However, achieving precise modulation of the ultrafine Pt nanoparticles coordination environment in conventional catalysts is challenging. In this work, we developed a unique “ring-shaped cavity induced” strategy to anchor the Ptx through the ring-shaped cavity of polyoxometalates (POMs) Na33H7P8W48O184 (denoted as P8W48). The NayPtx[P8W48O184] (PtxP8W48) was in-situ converted into abundant Pt/WO3-x heterostructure with Pt (∼2 nm) and highly depressed Pt-O-W heterointerfaces. Pt/WO3-x nanoparticles supported on highly conductive rGO exhibit superior HER activity. The overpotentials of the catalyst are only 2.8 mV and 4.7 mV at 10 mA·cm−2 in acidic water and seawater, far superior to commercial 20 % Pt/C catalyst. Additionally, the catalyst can be stabilized at a current density of 30 mA·cm−2 for 180 h. This study provides a feasible strategy for rational design of Pt-based catalysts for renewable energy applications.

A highly efficient and self-supporting nanoporous FeMoC catalyst for enhanced hydrogen evolution reaction

Optimizing structure and surface morphologies in electrocatalyst design are important to enhance the intrinsic activity of the hydrogen evolution reaction (HER). Mo-based phosphides and carbides have been confirmed as the widely-reported catalysts for HER. However, the origin of their enhanced catalytic activity is not fully clarified. Herein, the np-FeMoC and np-FeMoP with a self-supporting nanoporous structure were prepared using the melt-spinning and dealloying methods. Benefiting from the self-supporting electrode, nanoporous structure, abundant active species, low charge-transfer resistance and electron synergy, the np-FeMoC exhibits good catalytic performance. The np-FeMoC performs a low overpotential of 50.8 mV at 10 mA cm−2 current density for HER in 1 M KOH. This value is 2.7 times lower than that of the np-FeMoP sample, indicating a synergistic effect between Mo2C and Fe. From XPS and in-situ Raman results, it was observed that the dissolution of Mo2C occurs accompanied by dynamic evolution during the HER process on the np-FeMoC surface. This work unveils the intrinsic activity of Mo-based carbide and phosphide, providing valuable guidance for reasonable exploit of high-performance HER catalysts.

Titanium dioxide supported low-loading platinum as efficient and durable electrocatalyst for acidic hydrogen evolution reaction

Low-cost and high-performance catalysts towards hydrogen evolution reaction (HER) are essential in proton exchange membrane water electrolysers (PEMWE). Herein, an efficient and durable titanium dioxide supported low platinum-loading (TiO2-Pt) catalyst was fabricated. The prepared TiO2-Pt catalyst achieve an HER overpotential of 22 mV at 10 mA cm−2 and excellent durability performance in 0.5 M H2SO4. Electron transfer from TiO2 to Pt species and the presence of large amounts of proton on TiO2-Pt surface are verified, which facilitates the Heyrovsky step and promotes the HER activity of TiO2-Pt. The PEMWE with TiO2-Pt membrane electrode assemblies requires 1.65 V cell voltage to reach 1 A cm−2 and kept stable in 300 h continuous test. The electricity cost for hydrogen production by TiO2-Pt catalyst is below the US DOE requirements by 2026. This work provides a promising strategy for the synthesis of high-performance low Pt-loading HER catalysts for low-cost hydrogen production.