Catalytic Performance For Hydrogen Evolution Reaction Research Articles

MoS2 supported Ruthenium nanoparticles with abundant sulfur vacancies significantly improved hydrogen evolution reaction

The electrochemical hydrogen evolution reaction (HER) has become one of effective ways to produce hydrogen. MoS2 is a promising electrocatalyst for the HER, and loading noble metal atoms on MoS2 support can further enhance its HER activity. In present work, the CO was employed as a structure-directing agent to in situ synthesize MoS2-n (n = 0, 0.5, 1.0, 1.4 and 2.0 MPa, representing the CO pressure). Among them, the MoS2-1.4 with highest amounts of sulfur vacancies and superior alkaline HER performance was selected as the support for Ru loadings. Sulfur vacancies can stabilize Ru nanoparticles, prevent nanoparticles from aggregating, and facilitate the formation of small-sized nanoparticles. By optimizing the loading amounts of Ru, the 5Ru@MoS2-1.4 with the Ru loading of 5 wt.% and nanoparticle size of 2 nm exhibits the best alkaline HER activity by displaying a low overpotential of 55 mV and Tafel slope of 68.6 mV dec−1 at a current density of 10 mA cm−2 in 1.0 M KOH medium. This can be majorly related to the synergistic effect of MoS2-1.4 support and small-sized Ru nanoparticles, wherein the CO plays a significant role in regulating the structure of MoS2-1.4 support that favors dispersion of Ru nanoparticles. Generally, present work provides a strategy to enhance the HER catalytic performance of MoS2, which is favorable for other highly-efficient catalyst design.

Ordered PtNiTiZrHf nanoparticles on carbon nanotubes catalyze hydrogen evolution reaction with high activity and durability

With the scarcity of the earth's natural resources, hydrogen production from electrolyzing water is seen as an alternative energy source. Although platinum (Pt) is an advanced catalyst for hydrogen evolution reaction (HER), its application is limited by high cost and limited electrocatalytic performance. In this article, the five-element alloy nanoparticles are successfully synthesized on carbon nanotubes (CNT) by employing liquid-phase reduction and gas-phase sintering to reduce Pt utilization and improve catalytic performance. For comparison, a series of ordered and disordered (PtNi)x(TiZrHf)100-x/CNT catalysts are obtained. Results show that the ordered samples have more excellent HER catalytic performance and stability than disordered samples in 0.5 M H2SO4 and 1 M KOH electrolytes. In particular, when the electrolyte is acidic, the overpotentials of ordered (PtNi)55(TiZrHf)45/CNT at 10 and 100 mA cm−2 are 11 and 52 mV, with low Tafel slope of 37.73 mV dec−1. At 10 mA cm−2, the stabilization time can reach 58 h, which is much better than commercial Pt/C (20 wt.%). Density functional theory (DFT) calculation shows that ordered (PtNi)55(TiZrHf)45/CNT has lower hydrogen adsorption energy and activated water adsorption energy than disordered one, indicating better performance in both acidic and alkaline electrolytes. It is mainly attributed to the electronic coupling effect after ordering that makes the overall D-band center decrease. This work presents a cost-effective approach to optimize the structural design for acid-base HER electrocatalysts.

Theoretical and experimental investigations of vanadium pentoxide–based electrocatalysts for the hydrogen evolution reaction in alkaline media

AbstractA key approach towards better realization of intermittent renewable energy resources, namely, solar and wind, is green electrochemical hydrogen production from water electrolysis. In recent years, there have been increasing efforts aimed at developing noble metal-free electrocatalysts that are earth-abundant and electroactive towards hydrogen evolution reaction (HER) in alkaline electrolytes, wherein an initial water dissociation step is followed by a two-electron transfer cathodic reaction. Although relatively earth-abundant, vanadium-based electrocatalysts have been sparsely reported due to subpar electroactivity and kinetics towards water electrolysis in general and alkaline electrolysis in specific. Herein, we investigate the fine-tuning of orthorhombic V2O5-based electrocatalysts as candidates for HER through a scalable two-step sol–gel calcination procedure. Briefly, surface-induced anionic oxygen deficiencies and cationic dopants are synergistically studied experimentally and theoretically. To that end, first-principle facet-dependent density function theory (DFT) calculations were conducted and revealed that the coupling of certain dopants on V2O5 and co-induction of oxygen vacancies can enhance the catalytic HER performance by the creation of new electronic states near the Fermi level (EF), enhancing conductivity, and modulating surface binding of adsorbed protons, respectively. This was reflected experimentally through kinetically non-ideal alkaline electrochemical HER using Zn0.4V1.6O5 whereby − 194 mV of overpotential was required to attain − 10 mA/cm2 of current density, as opposed to pristine V2O5 which required 32% higher overpotential requirement at the same conditions. The disclosed work can be extended to other intrinsically sluggish transition metal (TM)–based oxides via the presented systematic tuning of surface and bulk microenvironment modulation. Graphical Abstract

Micro-mechanism investigation of hydrogen evolution reaction on anti-perovskite Ni3InN considering doping and strain effects

Anti-perovskites are considered as promising high-efficiency catalysts for hydrogen evolution reaction (HER) due to their low cost, adjustable composition, and small water dissociation kinetic barriers. Accounting strain effects, transition metal doping effects and solvent effects, we calculate HER micro-mechanism on anti-perovskite Ni3InN and conclude that HER on Ni3InN can be divided into two steps, rapid proton adsorption at the Bridge site and favorable H2 desorption at the Hollow site. We obtained 2 doping elements (Pt and Ir) from 20 transition metal elements that can enhance HER catalytic performance of Ni3InN. It is worth noting that applying a certain strain is beneficial for the catalytic performance of some doped Ni3InN (e.g. +2 %, +1% for Pt), while harmful for others (e.g. Ir). Our work provides a new perspective for the application of anti-perovskites in HER, which is meaningful for the development of HER catalysts.

Unusual Sabatier principle on high entropy alloy catalysts for hydrogen evolution reactions

The Sabatier principle is widely explored in heterogeneous catalysis, graphically depicted in volcano plots. The most desirable activity is located at the peak of the volcano, and further advances in activity past this optimum are possible by designing a catalyst that circumvents the limitation entailed by the Sabatier principle. Herein, by density functional theory calculations, we discovered an unusual Sabatier principle on high entropy alloy (HEA) surface, distinguishing the “just right” (ΔGH* = 0 eV) in the Sabatier principle of hydrogen evolution reaction (HER). A new descriptor was proposed to design HEA catalysts for HER. As a proof-of-concept, the synthesized PtFeCoNiCu HEA catalyst endows a high catalytic performance for HER with an overpotential of 10.8 mV at −10 mA cm−2 and 4.6 times higher intrinsic activity over the state-of-the-art Pt/C. Moreover, the unusual Sabatier principle on HEA catalysts can be extended to other catalytic reactions.

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.

Phase control of solid-solution RuIn nanoparticles and their catalytic properties.

The properties of solids could be largely affected by their crystal structures. We achieved, for the first time, the phase control of solid-solution RuIn nanoparticles (NPs) from face-centred cubic (fcc) to hexagonal close-packed (hcp) crystal structures by hydrogen heat treatment. The effect of the crystal structure of RuIn alloy NPs on the catalytic performance in the hydrogen evolution reaction (HER) was also investigated. In the hcp RuIn NPs, enhanced HER catalytic performance was observed compared to the fcc RuIn NPs and monometallic Ru NPs. The intrinsic electronic structures of the NPs were investigated by valence-band X-ray photoelectron spectroscopy (VB-XPS). The d-band centre of hcp RuIn NPs obtained from VB-XPS was deeper than that of fcc RuIn NPs and monometallic Ru NPs, which is considered to enable the hcp RuIn NPs to exhibit enhanced HER catalytic performance.

Pt nanoparticles anchored by oxygen vacancies in MXenes for efficient electrocatalytic hydrogen evolution reaction.

The improvement of the hydrogen evolution reaction (HER) performance of nanomaterials is associated with the interfacial synergistic interaction and their hydrogen adsorption kinetics. Nevertheless, it is still a challenge to accelerate the proton transfer and optimize the HER kinetics by constructing Pt-supported heterostructures based on the hydrogen spillover phenomenon. Herein, oxygen vacancies on the surface of MXene nanosheets were constructed via a high-temperature annealing method, which was employed to anchor/stabilize Pt nanoparticles and fabricate a Pt/MXene heterostructure. EPR and XPS analyses verified the presence of oxygen vacancies, which could enhance the intrinsic HER activity of the MXene. The HER catalytic performance was investigated by taking into account the surface structure of the MXene affected by the annealing temperature, the concentration of Pt and the number of deposition cycles. Electrochemical results showed that Pt/MXene with higher utilization of Pt was obtained at 900 °C and 0.05 mgPt mL-1. The 0.05-Pt/MXene-900 obtained at deposition of 60 cycles in 0.5 M H2SO4 solution exhibited the optimized HER activity. The overpotential was 22 mV at a current density of 10 mA cm-2 and the Tafel slope was 42.41 mV dec-1. Furthermore, the accelerated HER kinetics was mainly due to the electron trapping ability of the MXene, small particles of Pt, as well as the enhanced charge transfer between the oxygen vacancies of the MXene and Pt. This strategy for constructing Pt-supported heterostructures based on the vacancy anchoring effects provides new ideas for the design of well-defined electrocatalysts toward the HER.

S dopant-mediated hydrogen evolution reaction activity of CoSe2

CoSe2 has become one of the most appealing non-noble metal catalysts for hydrogen evolution reaction (HER) in the field of electrolysis water due to its abundant resources and good activity. Inversely, its slow kinetic behavior is still restrained, which plays a negative influence for high-efficiency HER. Herein, a certain of Ni or S was introduced into the (100) crystal facet of CoSe2 on the basis of density functional theory (DFT) calculations. Thermodynamic calculation results reveal that the HER activity for CoSe1S1 is relatively better than those of Ni0.375Co0.625Se2 and pristine CoSe2 when a certain of S atoms were introduced into CoSe2. More strikingly, the active sites of CoSe1S1 are reversed from cationic Co to anion S, which is close to the ideal value (0) of Gibbs free energy. Meanwhile, the kinetic performance of H adsorbed on the anionic S or Se site is optimal, and their migration energy barrier is lower in comparison with 1/2 of the cationic Co site. According to the electronic structure analysis, the conductivity of CoSe1S1 is prominent than other counterparts (such as Ni0.375Co0.625Se2 and CoSe2). This work indicates that CoSe1S1 exhibits an excellent catalytic performance for HER, and offers theoretical guidance in the aspect of experiments for designing high-efficient HER catalysts.

Computational screening of oxygen and sulfur decorated MXene supported transitions metal single-atom catalysts for hydrogen evolution reaction

Herein, we systematically performed the comparative analysis of 24 transition metals single-atom catalysts (SACs) supported on MXene (Mo2CT2; T = O or S) surface for hydrogen evolution reaction (HER) and investigated their electronic structures, geometries, stabilities, selectivity, and catalytic activities by using first-principles calculations. The molecular dynamics and thermal stabilities of MXene (Mo2CO2 and Mo2CS2) monolayers were first investigated by using AIMD simulations and phonon dispersion spectra. Based on the Volmer-Heyrovsky pathway, TM/Mo2CO2 (TM = Ti, V, Cr, Co, Mo, Tc, Ru) and TM/Mo2CS2(TM = Cr, Mn, Fe, Zn, Tc, Ru, W, Pt) SACs exhibited good catalytic performance for HER and their ΔGH* values are close to the optimum value (ΔGH* → 0). The calculated ΔGH* values of Ti/Mo2CO2, Mo/Mo2CO2, Tc/Mo2CO2, Ru/Mo2CO2, Zn/Mo2CS2, W/Mo2CS2, Cr/Mo2CS2, and Pt/Mo2CS2 are equal or better than Pt (111) catalyst, making them active and selective catalysts for HER. Moreover, Mo/Mo2CO2 and Pt/Mo2CS2 catalysts exhibited outstanding catalytic performance towards HER much better than the Pt (111) catalyst. Therefore, the present investigation would provide a useful guideline for experimentalists to design MXene-based transition metals SACs for HER and other electrochemical applications.

A heterostructure of interlayer-expanded 1T phase MoS2 and spherical MoO2 for efficient and stable hydrogen evolution

The inferior hydrogen evolution reaction (HER) catalytic performance of MoS2 can be attributed to its small edge ratio, large inert substrate surface, and poor electrical conductivity, while the multiple strategies are expected to be employed simultaneously to modulate the electronic structure of MoS2 and yield catalysts with superior HER catalytic performance. Here, we report a MoS2 containing a 1 T phase with expanded layer spacing and construct it as a heterostructured material with MoO2 (MoO2 @E-MoS2). Specifically, the presence of the 1 T phase and expanded layer structure of MoS2 can enhance electrode conductivity, increase active site exposure, promote H2O adsorption, and optimize the Gibbs-free energy of hydrogen. The constructed heterostructure can modulate the electronic structure of the catalyst, enhance electron transfer at the interface, elevate water adsorption energy, and reduce the hydrogen reaction energy barrier. Moreover, density functional theory calculations indicate that the S site of MoS2 in this catalyst exhibits a higher affinity for H2O adsorption, while the Mo site demonstrates a greater capacity for H* adsorption/desorption. Ultimately, MoO2 @E-MoS2 shows low overpotentials of 93 and 99 mV at a current density of 10 mA cm−2, as well as exceptional long-term stabilities exceeding 70 and 130 h at current densities ranging from 10 to 30 mA cm−2 in acidic and alkaline media, respectively.

Enhancement of hydrogen evolution activity by tailoring the electronic structure in ruthenium-heteroatom-doped cobalt iron phosphide nanoframes

Designing cost-effective and highly efficient electrocatalysts for hydrogen evolution reaction (HER) in alkaline media at high current densities is challenging. In this study, we adopted Ru heteroatom doping and an open nanoframe structure to obtain excellent HER catalytic performance. X-ray photoelectron spectroscopy (XPS) visualized the electron transfer due to Ru heteroatom doping in transition metal phosphides, to observe the modulated electronic structure of the Ru-doped CoFeP nanoframe (RCFP/NF). Density functional theory (DFT) calculations and XPS analysis confirmed a d-band center downshift of the RCFP/NF, demonstrating the regulation of the optimal adsorbates (OH*/H*) adsorption free energies. Consequently, RCFP/NF with 4.7 wt % of Ru exhibits a low overpotential of 112 mV, 191 mV, and 219 mV at current densities of 10 mA cm−2, 100 mA cm−2, and 500 mA cm−2, respectively, and an excellent stability for 100 h at a high current density of 100 mA cm−2. This outstanding HER performance at high current density was attributed to the hydrophilic and aerophobic properties of the RCFP/NF catalyst surface that facilitate the exposure of active sites and H2 gas desorption.

Probing Active Sites on Pristine and Defective MnPX3 (X: S and Se) Monolayers for Electrocatalytic Water Splitting.

The state-of-the-art density functional theory approach was used to study the structural and electronic properties of pristine and defective MnPX3 monolayers as well as their activity toward water and hydrogen evolution reaction (HER) catalytic performance. The adsorption behavior of H2O on a pristine MnPX3 structure is of physisorption nature, whereas the adsorption energy is significantly increased for the defective structures. At the same time, the water dissociation process is more energetically favorable, and the reactivity of MnPX3 is determined by the vacancy configuration. Following Nørskov's approach, the HER catalytic performance is evaluated by calculating the hydrogen adsorption free energy on the respective MnPX3 surface. Our calculation results demonstrate that defective 2D MnPX3 with low coordinated P shows significantly higher HER performance compared to the pristine counterpart.

Photocatalytic splitting of water on g-C3N4-based single-atom Pt catalysts with stable “sandwich” structure: a combined first principles and semi-empirical investigation

Solar-to-hydrogen energy conversion is a promising strategy to solve environmental pollution and energy crisis by utilizing photocatalytic water splitting. In this work, a “sandwich” structure of g-C3N4-based single-atom platinum (Pt) catalyst for photocatalytic water splitting is proposed and investigated using a combined first principles and semi-empirical study method. The calculation results indicate that, without any co-catalyst, the photogenerated holes in the valence band of BL-g-C3N4 cannot oxidize H2O to O2, and its oxygen evolution reaction (OER) performance is not better than that of the pristine monolayer g-C3N4. Significantly, the photogenerated holes in the valence band of the “sandwich”-structured photocatalyst g-C3N4–Pt1–g-C3N4 can oxidize H2O to O2 without any co-catalyst. That is, the OER performance of g-C3N4–Pt1–g-C3N4 is better than that of the pristine g-C3N4 and the pristine bilayer-g-C3N4 (BL-g-C3N4). However, it can be found that the introduction of single Pt atom confinement in the BL-g-C3N4 cannot effectively reduce hydrogen evolution reaction (HER) energy barrier or improve the hydrogen evolution kinetics of BL-g-C3N4. In other words, the introduction of the confined single Pt atom in the BL-g-C3N4 not only fails to improve HER performance of BL-g-C3N4, but deteriorates HER catalytic performance of BL-g-C3N4. These findings provide some theoretical insights for engineers to prepare photocatalysts with higher activity and stability.

Enhanced Alkaline Hydrogen Evolution on Gd1.0/Ndx (x = 0.5, 1.0, 3.0, and 6.0%)-Doped TiO2 Bimetallic Electrocatalysts

The work reports a facile synthesis of high thermally stable nanocrystalline anatase TiO2 nanoparticles (NPs) doped with different atomic concentrations (0.5, 1.0, 3.0, and 6.0%) of Gd3+ and Nd3+ ions by a template-free and one-step solvothermal process, using titanium(IV) butoxide as a titanium precursor and dimethyl sulfoxide (DMSO) as a solvent. The structure and morphology of the Gd3+, Nd3+, and 0.5%Gd3+-0.5%Nd3+/doped TiO2 NPs have been characterized by using various analytical techniques. The Gd3+/ and Nd3+/TiO2 molar ratios were found to have a pronounced impact on the crystalline structure, size, and morphology of TiO2 NPs. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) studies revealed the proper substitution of Ti4+ by Gd3+ and Nd3+ ions in the TiO2 host lattice. The as-prepared Gdx/TiO2, Ndx/TiO2, and Gd1.0/Ndx/TiO2 bimetallic NPs, x = 0.5, 1.0, 3.0, and 6%, have been investigated as electrocatalysts for hydrogen evolution reaction (HER) in 1.0 M KOH solution using a variety of electrochemical techniques. At any doping percentage, the Gd1.0/Ndx/TiO2 bimetallic NPs showed higher HER catalytic performance than their corresponding counterparts, i.e., Gdx/TiO2 and Ndx/TiO2. Upon increasing the Nd content from 0.5 to 6.0%, the HER catalytic performance of the Gd1.0/Ndx/TiO2 bimetallic NPs was generally enhanced. Among the studied materials, the bimetallic Gd1.0/Nd6.0/TiO2 NPs emerged as the most promising catalyst with an onset potential of −22 mV vs. RHE, a Tafel slope of 109 mV dec−1, and an exchange current density of 0.72 mA cm−2. Such HER electrochemical kinetic parameters are close to those recorded by the commercial Pt/C (onset potential: −15 mV, Tafel slope: 106 mV dec−1, and exchange current density: 0.80 mA cm−2), and also comparable with those measured by the most active electrocatalysts reported in the literature. The synergistic interaction of Gd and Nd is thought to be the major cause of the bimetallic catalyst’s activity.

Ultrafine PtMo Nanocrystals Confined on N‐Doped Carbon Toward Efficient pH‐Universal Hydrogen Evolution Reaction

AbstractPt‐based nanocrystals with tunable electronic structure and optimized atom efficiency are essential for boosting the hydrogen evolution reaction (HER) performance and further industrial application. However, the synthesis of uniform and ordered nanocrystals is still a challenge due to the uncontrollable size growth of metal particles, restricting the active sites toward the desired catalytic activity. Herein, the synthesis of ultrafine bimetal PtMo nanocrystals on N‐doped carbon (PtMo‐NC) through an anchoring‐sites engineering strategy is reported, in which the N‐rich carbon can provide abundant sites to anchor the metal atoms and suppress the over aggregation. The PtMo‐NC catalyst exhibits superior HER performance in both alkaline and acidic conditions, delivering a smaller overpotential (80 mV and 63 mV) at a current density of 100 mA cm−2 in alkaline and acidic media. Theoretical calculations reveal that the introduction of Mo atom into Pt can reduce the energy barrier of water molecule dissociation and optimize the H intermediate absorption strength on Pt sites, thus boosting the catalytic HER performance. This study offers a universal strategy to design ultrafine nanocatalysts to achieve high‐efficiency electrocatalysis.

Controllable tuning graphene composited PtCoYOx nanocomposites to promote electrocatalytic hydrogen evolution

Water electrolysis powered by renewable energy is regarded as the feasible route for the production of hydrogen, which was obtained at the cathode side through electrochemical hydrogen evolution reaction (HER). Herein, we proposed a novel strategy to achieve high and stable HER catalytic performance by designing graphene coatings shaped like a flower trimetallic PtCoYOx @G nanoparticles with multiple petals and by adjusting the composition ratio of PtCoYOx @G (0.1:0.05:0.1). Compared with the bimetallic PtYO@G catalysts, the trimetallic PtCoYOx @G catalysts showed superior HER performance with an overpotential of 106 mV at 10 mA cm−2, a Tafel slope of 38.08 mV dec−1, and long-term stability of 25 h. Electron paramagnetic resonance (EPR) tests exhibited strong signal peaks and aerobic vacancies in PtCoYOx @G materials. Density functional theory (DFT) calculation revealed that Co doping increased the active site of the catalyst, resulting in excellent charge density with good conductivity. Therefore, the doping of Co in trimetallic PtCoYOx @G was the key to improve HER catalytic activity.

Control of the metal-support interactions in Ru on N-doped graphene-encapsulated Ni nanoparticles to promote their hydrogen evolution reaction catalytic performance

Controlling metal-support interaction (MSI) is considered as an effective strategy to optimize the electronic structure of catalysts and thus promote their catalytic performance. Here, with the strong MSI by both metal core and nitrogen-doped carbon shell, the synthesized Ru supported on N-doped graphene-encapsulated Ni nanoparticles (Ni@NC/Ru) show excellent performance towards hydrogen evolution reaction (HER). It exhibits a very low HER potential of 28 mV at the current density of 10 mA cm−2, and high durability that the potential only increases approximately 7 mV after 10,000 cyclic voltammetry cycles. The high HER performance is attributed to the strong MSI from the tuning effect of Ni metal core and N-dope graphene shell, which optimizes the hydrogen binding energy of the catalysts. This study may shed light on the rational design of superior HER catalysts.

Tunable Pt-Ni Interaction Induced Construction of Disparate Atomically Dispersed Pt Sites for Acidic Hydrogen Evolution.

Developing cost-effective Pt-based electrocatalysts for the hydrogen evolution reaction (HER) is highly urgent. Herein, we report novel electrocatalysts with individually dispersed Pt active sites and tunable Pt-Ni interaction decorated on carbon-wrapped nanotube frameworks (Pt/Ni-DA). Pt/Ni-DA exhibits superior HER performance at low Pt concentrations with an ultralow overpotential of 18 mV at 10 mA cm-2 and an ultrahigh mass activity of 2.13 A mgPt-1 at an overpotential of 50 mV, which is about four times higher than that of commercial Pt/C. X-ray absorption fine structure (XAFS) confirms the extension of Pt from the Ni surface to the Ni bulk phase. Mechanistic research and density functional theory (DFT) calculations collectively reveal that the dispersibility and distribution of Pt atoms in Ni regulate the electronic configuration of Pt sites, optimizing the binding energy of reaction intermediates and facilitating electron transfer during the HER process. This work highlights the importance of the electronic structure alternation through the accommodation effect toward enhanced catalytic performance in HER.