Nickel Molybdenum Research Articles

Effects of molybdenum and cobalt alloying on corrosion resistance of electrochemical coatings based on the Ni–W system

The paper studies coatings of the Ni–W system alloyed with molybdenum and cobalt obtained by electrodeposition. The effect of the concentration of salts of the alloying element in the electrolyte on the chemical composition of the coatings was studied under various synthesis conditions. All the obtained coatings are nanocrystalline or amorphous solid solutions of tungsten, molybdenum or cobalt in nickel with a FCC crystal lattice. Polarization measurements made it possible to establish that the most resistant to corrosion in a 3.5% NaCl solution is a coating containing 35% W and 8% Mo.

Engineering 4f-2p-3d orbital hybridization on cerium-doped nickel–molybdenum phosphates for energy-saving hydrogen evolution

Engineering 4f-2p-3d orbital hybridization on cerium-doped nickel–molybdenum phosphates for energy-saving hydrogen evolution

Sulfide Route to Chromium–Nickel–Molybdenum Ferroalloys for Stainless Steel Production

AbstractNew methods of materials separation and metal production utilizing sulfide chemistries may support a paradigm shift in sustainable metallurgy. We leverage sulfidation with elemental sulfur, aluminothermic reduction, and slag refining to obtain a chromium–nickel–molybdenum ferroalloy and stainless steel using a sulfide-based route without direct greenhouse gas emissions. The absence of carbothermic reduction from the mineral, concentrate, and matte feedstocks tried herein indicates that argon-oxygen-decarburization may no longer be necessary to refine stainless steel products.

Erratum to: Surface curvature-confined strategy to ultrasmall nickel–molybdenum sulfide nanoflakes for highly efficient deep hydrodesulfurization

Erratum to: Surface curvature-confined strategy to ultrasmall nickel–molybdenum sulfide nanoflakes for highly efficient deep hydrodesulfurization

Extraction of molybdenum, cobalt, and nickel from acidic leach solution of molybdenum leach residue of spent hydrodesulfurization catalyst

ABSTRACT After the extraction of molybdenum from the spent HDS catalyst, a residue containing aluminum, nickel, cobalt, and a small amount of molybdenum was obtained. The simultaneous recovery of nickel, cobalt, aluminum, and residual molybdenum from molybdenum leach residue can be achieved through hydrochloric acid leaching. In the work presented herein, the extraction of molybdenum, cobalt, and nickel from the acidic leach solution of molybdenum leach residue was investigated. Trioctyl tertiary amine can selectively extract cobalt and molybdenum from the acidic leach solution, the extraction of both cobalt and molybdenum reached more than 99% after two-stage countercurrent extraction. The combination of pure water and 25% ammonia water can be utilised for the separation and extraction of cobalt and molybdenum from the loaded cobalt-molybdenum organic phase. After the extraction of cobalt and molybdenum, a synergistic extraction system comprising decyl 4-picolinate and dinonylnaphthalene sulfonic acid can be employed for nickel extraction, achieving a nickel extraction exceeding 99.70% while maintaining aluminum extraction at only 0.32% after undergoing four-stage countercurrent extraction. The nickel stripping efficiency can reach 99.50% after four-stage countercurrent stripping, using a stripping agent of 2 mol/L H2SO4.

Nickel Molybdenum Selenide (NiMoSe2) Nanostructures: A Binary Transition Metal Dichalcogenide for Regioselective Synthesis of 2,3,5‐Tri Substituted Pyrrole Derivatives

AbstractBinary transition metal dichalcogenides (BTMDs) have attracted a lot of researchers to exploit their unique properties for different applications in various fields, mainly in energy and environment. Surprisingly, there are no attempts of utilizing BTMDs materials particularly nickel molybdenum selenide (NiMoSe2) as a catalyst support for organic transformations. Reusable catalysts are better alternatives to the transition metal‐free protocols for the synthesis of heterocyclic compounds. Herein, we report a NiMoSe2 BTMD catalyst with Lewis acidic (transition metal) and strongly basic (selenide) sites for the regioselective synthesis of 2,3,5‐tri(het)aryl‐pyrroles from β‐thioxoketone precursors. The present method is capable of giving the expected products in good to excellent yields (up to 80%). Different substituents like ester, cyano, alkyl, trifluoromethyl, methoxy, and halogens have shown tolerance under optimized reaction conditions. The recyclability and reusability of the catalyst was checked for five catalytic cycles without notable loss in reactivity.

Enhancing the electrochemical performance of a nickel molybdenum nitride for an energy storage device using cobalt nitride and phosphorus doping

Compared to traditional energy storage devices, hybrid solid-state supercapacitors have gained a lot of attention because of their exceptional power, energy density and outstanding cyclic stability. Transition metal nitrides are eminent candidates with high-performance electrochemical properties for energy storage devices. In this work, a high-performance CoN/NiMoN interface with P-doping was prepared by a simple feasible strategy for the positive electrode of a supercapacitor. The electrochemical performance in a 2 M KOH electrolyte revealed a specific capacity of 2070C·g−1 at a 5 A·g−1, which is exceptional compared to recently reported literature. Encapsulating NiMoN with CoN and its P-doping, resulting in a three-dimensional structure with desirable textural properties and easy permeation of electrolyte, enhances the electrochemical performances prepared electrode. Further, a hybrid solid-state supercapacitor was prepared with P-CoN/NiMoN (positive) and activated carbon (negative) as a electrodes. The prepared P-CoN/NiMoN//activated carbon supercapacitor showed an operating potential window of 1.7 V with an admirable specific capacity of 573.99C·g−1, for 135.5 Wh·kg−1 energy and 850 W·kg−1 power density at a 1 A·g−1. The results provide a feasible strategy to prepare and modify the electrochemical properties of NiMoN by CoN encapsulation and P-doping. The method gives insights for the preparation of other transition metal nitrides for high-density energy storage without much change in the power density.

Surface active sites and interphase engineering into metal oxide hydrates enabled by ions substitution for efficient water splitting

The expanding requirement of energy-effective and cost-efficient water electrolysis has prompted studies of earth-abundant metal-based electrocatalysts. In this study, we study the typical substitution strategies of cation (Pt) or anion (Se) for modifying surface active sites or interphase engineering to tune electronic structure of bimetallic nickel molybdenum oxide hydrates (NiMoO4·xH2O), thus effectively improving catalytic properties toward hydrogen evolution reaction (HER) or oxygen evolution reaction (OER). Result of the cation substitution achieves PtSA–NiMoO4·xH2O catalyst with abundant doped Pt single atoms on surface, which promotes high HER activity with a small overpotential of 73 mV at a current yield of 10 mA cm−2 in alkaline medium. Meanwhile, Se–NiMoO4·xH2O catalyst, an outcome of the anion substitution approach, has unique interfaces of NiSe-NiMoO4 heterostructure and thus exhibits a desired overpotential of only 297 mV for OER. The combination of PtSA–NiMoO4·xH2O(–)//Se–NiMoO4·xH2O(+) couple results in a two-electrode electrolyzer cell, which requires a small cell voltage of 1.48, 1.54 and 1.59 V to deliver a response of 10 mA·cm−2 at 75, 50 and 25 °C, respectively, along with negligible performance decay during 50 h operation. These results highlight the potential of our catalyst engineering strategies to achieve high-performance green hydrogen production.

Construction of ultra-thin NiMo3S4 nanosheet sphere electrode for high-performance hybrid supercapacitor

The construction of electrode materials with rational morphology and structure based on bimetallic sulfides is crucial to improve the performance of supercapacitors. Ultra-thin three-dimensional nickel molybdenum sulfide nanosheet spheres (NiMo3S4 NSSs) are grown on nickel foam (NF) using a one-step hydrothermal synthesis. NiMo3S4 NSSs have a diameter of ∼ 5 μm and nanosheet thickness of 200 nm. The effects of increasing the hydrothermal synthesis time and molar concentration ratios of Ni2+ to MoO42- on the morphologies of the NiMo3S4 are investigated. Due to the synergistic effect of NiMo3S4 NSSs and bimetallic ions which can provide a larger solution contact areas and improve the redox activity, the electrode exhibits good electrochemical properties. The specific capacity of NiMo3S4 NSSs/NF electrode can reach 1002.4 C/g (1 A/g). After being assembled into a hybrid supercapacitor (HSC) with activated carbon (AC), the energy density can reach 72.1 Wh/kg at the power density of 749.9 W/kg. In addition, the HSC shows an excellent stability of 89 % after 10, 000 charge-discharge cycles (10 A/g).

Engineering Robust Triazine Crosslinked and Pyridine Capped Anion Exchange Membrane for Advanced Water Electrolysis.

Exploring high-performance anion exchange membranes (AEM) for water electrolyzers (AEMWEs) is significant for green hydrogen production. However, the current AEMWEs are restricted by the poor mechanical strength and low OH- conductivity of AEMs, leading to the low working stability and low current density. Here, we develop a robust AEM with polybiphenylpiperidium network by combining the crosslinking with triazine and the capping with pyridine for advanced AEMWEs. The AEM exhibits an excellent mechanical strength (79.4 MPa), low swelling ratio (19.2 %), persistent alkali stability (» 5,000 hours) and high OH- conductivity (247.2 mS cm-1) which achieves the state-of-the-art AEMs. Importantly, when applied in AEMWEs, the corresponding electrolyzer equipped with commercial nickel iron and nickel molybdenum catalysts obtained a current density of up to 3.0 A cm-2 at 2 Vand could be stably operated ~430 h at a high current density of 1.6 A cm-2, which exceeds the most of AEMWEs. Our results suggest that triazine crosslinking and pyridine capping can effectively improve the overall performance of the AEMWEs.

Engineering Robust Triazine Crosslinked and Pyridine Capped Anion Exchange Membrane for Advanced Water Electrolysis

Exploring high‐performance anion exchange membranes (AEM) for water electrolyzers (AEMWEs) is significant for green hydrogen production. However, the current AEMWEs are restricted by the poor mechanical strength and low OH‐ conductivity of AEMs, leading to the low working stability and low current density. Here, we develop a robust AEM with polybiphenylpiperidium network by combining the crosslinking with triazine and the capping with pyridine for advanced AEMWEs. The AEM exhibits an excellent mechanical strength (79.4 MPa), low swelling ratio (19.2 %), persistent alkali stability (» 5,000 hours) and high OH‐ conductivity (247.2 mS cm‐1) which achieves the state‐of‐the‐art AEMs. Importantly, when applied in AEMWEs, the corresponding electrolyzer equipped with commercial nickel iron and nickel molybdenum catalysts obtained a current density of up to 3.0 A cm‐2 at 2 V and could be stably operated ~430 h at a high current density of 1.6 A cm‐2, which exceeds the most of AEMWEs. Our results suggest that triazine crosslinking and pyridine capping can effectively improve the overall performance of the AEMWEs.

Flexible Ni-Foam-Based Electrode with Novel MoS2/NiO Nanocomposite for Superior Supercapacitor Applications

Abstract In the present work a simple and effective hydrothermal method has been used to synthesize a nanocomposite of nickel oxide and molybdenum disulphide. Structural and optical characterizations of the as-synthesised MoS2/NiO nanocomposite nanoparticles were carried out using X-ray diffraction (XRD) and UV-visible spectroscopy techniques. The major peaks of MoS2 and NiO were detected in XRD, confirming the formation of composite. The reduced band gap 2.84 eV of MoS2/NiO nanocomposite as compared to pure NiO with 3.1 eV bandgap indicates a blue shift. Surface morphology of MoS2/NiO nanocomposite was measured using field-emission scanning electron microscopy, showing sheet-like structure with fine particle over laid on them. Cyclic voltammetry and electrochemical impedance spectroscopy (EIS) were used to determine the processes of charge transfer in between electrodes, diffusion of molecules and ions within the electrolyte solution , and ion adsorption on an surface of electrode. The as-prepared composite shows enhanced specific capacitance of 246 F/g at scan rate of 20 mV/sec which was more than both base materials in pristine form. EIS results thus obtained may give a new direction for supercapacitor applications with the as-synthesized sample.

Exploring the Role of Coordinating Environments on Durability of Nickel-Based Catalysts for Hydrogen Evolution Reactions

Ni-based platinum-group-metal (PGM)-free catalysts for hydrogen evolution reaction have been considered viable for the commercialization of alkaline exchange membrane water electrolysis (AEMWE) due to their high activity and low cost. Even though several highly active Ni-based catalysts have been developed in recent years, their long-term stability under commercially relevant conditions was not systematically assessed, preventing a direct comparison with the currently used catalysts. While not as active, the current commercial PGM-free catalysts are highly stable, with an operational life measured in decades. However, conducting durability assessments through long-term durability studies can take over 10,000 hours which is impractical. Consequently, accelerated stress tests (ASTs) specifically targeting the catalyst and simulating uncontrolled shutdown and high overpotential scenarios are needed to further improve AEMWE technology.In this presentation, the ASTs of several Ni-based catalysts with different coordination environments (nickel molybdenum, nickel cupferron1, Ni-NiO, and a novel high surface area de-alloyed Ni catalyst) will be explored. The catalysts were subjected to high overpotentials and uncontrolled shutdown cycles in both liquid electrolyte and AEMWE cells. The structure of these catalysts was observed using in situ Raman spectroscopy, XRD, TEM, and BET gas adsorption analysis and correlated to changes in electrochemical performance. The determination of the catalyst structure during these ASTs is paramount in designing durable PGM-free catalysts for improved AEMWE performance.1) Doan, H.; Kendrick, I.; Blanchard, R.; Jia, Q.; Knecht, E.; Freeman, A.; Jankins, T.; Bates, M. K.; Mukerjee, S. Functionalized Embedded Monometallic Nickel Catalysts for Enhanced Hydrogen Evolution: Performance and Stability. J. Electrochem. Soc. 2021, 168 (8), 084501. https://doi.org/10.1149/1945-7111/ac11a1.

Towards High-Performance AEM Water Electrolyzers: Transitioning from PGM to Low-PGM and PGM-Free Electrocatalysts

Hydrogen, known for its high gravimetric energy density and low environmental impact, is widely regarded as a promising low-carbon energy carrier. The production of hydrogen via water electrolysis offers a valuable opportunity to efficiently utilize renewable energy resources – both as a storage and transport medium and to produce hydrogen that is a crucial feedstock for multiple industrial and manufacturing applications. Among various water electrolysis technologies, anion exchange membrane water electrolyzers (AEMWEs) are notable for their distinct and advantageous features. Their alkaline operational environment significantly reduces corrosion, allow for the possibility to use catalysts and cell component materials that are earth abundant and cost effective. Moreover, the use of anion exchange membranes (AEMs) as the electrolyte and zero-gap design enhance operational efficiency and hydrogen production rates compared to traditional alkaline electrolyzers. These benefits position AEMWEs as a compelling solution for efficient, cost-effective large-scale hydrogen production.To date, the development of lower-cost AEMWEs has been hindered by several challenges. A critical issue is the activity and durability of catalysts, particularly those that are platinum group metal (PGM)-free. This leads many researchers and electrolyzer manufacturers to lean on PGM catalysts at both the anode and cathode. These catalysts, while effective, significantly increase the cost and complexity of the system, posing a barrier to widespread adoption and commercialization of AEMEL technology in the burgeoning hydrogen economy. PGM-free anodes have been demonstrated for the AEMWE, but there have been fewer PGM-free options for the cathode.This study assessed the performance and durability of various low-PGM and PGM-free electrocatalysts for the oxygen evolution (OER) and hydrogen evolution (HER) reactions. We focused on Lanthanum Strontium Cobalt (LSC), Nickel Ferrite (NiFeOx), and Lead Ruthenate (PbRuOx) for the OER at the anode, and Nickel Molybdenum (NiMo), Nickel Rhenium (NiRe), and a low-PGM PtNi for the HER at the cathode. Furthermore, the performance of the NiMo HER catalyst was enhanced by optimizing the physical properties of both the catalyst powder and the electrodes. These experimental results offer crucial insights into developing PGM-free AEM water electrolyzer systems, marking a progressive step towards their commercial feasibility.

Transformative impact of molybdenum on nickel phosphate hydrate electrodes towards superior energy storage application

Development of high capacity and long cycle life electrode materials is essential to improving energy storage capacity in electrochemical rechargeable devices. In order to be commercially viable, the synthesis of these materials must be straightforward, cost-effective, and ideally a single-step process. We present a binder-free synthesis method for nickel phosphate hydrate (NiPH) and nickel molybdenum phosphate hydrate (NiMoPH) on nickel foam via a simple hydrothermal process. X-ray diffraction (XRD) patterns confirmed the formation of NiPH and NiMoPH phases, while X-ray photoelectron spectroscopy (XPS) verified the presence of nickel (Ni), molybdenum (Mo), phosphorus (P), and oxygen (O) in the composite. Scanning electron microscopy (FE-SEM) revealed the formation of micro-flowers with plate-like structures in NiPH, which transformed into hexagonal rod-like structures upon the introduction of molybdenum in NiPH. This morphological and phase modification increased the charge storage capacity from 1441 mF/cm2 (NiPH) to 2945 mF/cm2 (NiMoPH) at 20 mA/cm2. The NiMoPH electrode demonstrated excellent capacitance retention of 91.8 % over 10,000 cycles. Additionally, asymmetric supercapacitor (ASS) devices were fabricated using NiPH and NiMoPH as positive electrodes and activated carbon (AC) as the negative electrode. The NiPH//AC and NiMoPH//AC configurations exhibited energy densities of 0.086 and 0.201 mWh/cm2, respectively, with the NiMoPH//AC device maintaining about 90 % capacitance retention over 15,000 cycles. This study demonstrates the potential of incorporating conductive transition metals to enhance electrode material performance in energy storage applications.

NiMo₂S₄-VS₂ heterostructure on nickel Foam: A promising electrocatalyst for alkaline oxygen evolution reaction

Oxygen Evolution Reaction (OER) is a slow process; therefore, improved kinetics require catalytic active centers and higher charge transfer capacities. In the present study, a novel heterostructure made of nickel molybdenum sulfide and vanadium disulfide supported on nickel foam (NiMo2S4-VS2/NF) substrate is fabricated using a single-step hydrothermal process. The structural, morphological, elemental, and textural properties of the fabricated materials are confirmed via various analytical techniques. Furthermore, at the current density of 10 mA cm−2, the observed overpotentials was approximately 318 mV corresponding to an OER in 1 M potassium hydroxide electrolyte. It also shows a lower Tafel slope of 78 mV/dec with large turnover frequency of 2.56 s−1. The resulting NiMo2S4-VS2/NF showed enhanced charge transfer properties and frequent integrated active sites. Hence the remarkable activity of this catalyst is significantly influenced by the synergistic effect of these combined features and resulted in an efficient overall water splitting. This was ascribed to NiMo2S4 which increases OER at the anode by providing active sites for oxidizing water molecules. In NiMo2S4, Mo and S elements aid to maintain active sites and accelerate reaction kinetics, while Ni sites operate as electrocatalytic efforts for water oxidation. In general, VS2 promotes hydrogen atom recombination into molecular hydrogen while also encouraging HER at the cathode via hydrogen atom adsorption. In general, NiMo2S4-VS2/NF is a suitable option for water splitting applications due to the close proximity of these two components within the structure of the catalyst, which enables charge transfer and surface reactions and also allow for effective OER. This unique approach for designing the catalyst and engineering the heterointerface is a promising strategy to develop novel and efficient OER catalysts.

Copper permalloys for fluxgate magnetometer sensors

Abstract. Fluxgate magnetometers are commonly used to provide high-fidelity vector magnetic field measurements. The magnetic noise of the measurement is typically dominated by that intrinsic to a ferromagnetic core used to modulate (gate) the local field as part of the fluxgate sensing mechanism. A polycrystalline molybdenum–nickel–iron alloy (6.0–81.3 Mo permalloy) has been used in fluxgates since the 1970s for its low magnetic noise. Guided by previous investigations of high-permeability copper–nickel–iron alloys, we investigate alternative materials for fluxgate sensing by examining the magnetic properties and fluxgate performance of that permalloy regime in the range 28 %–45 % Cu by weight. Optimizing the alloy constituents within this regime enables us to create fluxgate cores with both lower noise and lower power consumption than equivalent cores based on the traditional molybdenum alloy. Racetrack geometry cores using six layers of ∼30 mm long foil washers consistently yield magnetic noise around 4–5 pT/Hz at 1 Hz and 6–7 pT/Hz at 0.1 Hz, meeting the 2012 1 s INTERMAGNET standard of less than 10 pT/Hz noise at 0.1 Hz.

Pseudocapacitance Powered Nickel Molybdenum Nitride Nanocomposite Reactively Cosputtered on Stainless-Steel Mesh toward Advanced Flexible Supercapacitors

Pseudocapacitance Powered Nickel Molybdenum Nitride Nanocomposite Reactively Cosputtered on Stainless-Steel Mesh toward Advanced Flexible Supercapacitors

Precious Metal Free Hydrogen Evolution Catalyst Design and Application.

The quest to identify precious metal free hydrogen evolution reaction catalysts has received unprecedented attention in the past decade. In this Review, we focus our attention to recent developments in precious metal free hydrogen evolution reactions in acidic and alkaline electrolyte owing to their relevance to commercial and near-commercial low-temperature electrolyzers. We provide a detailed review and critical analysis of catalyst activity and stability performance measurements and metrics commonly deployed in the literature, as well as review best practices for experimental measurements (both in half-cell three-electrode configurations and in two-electrode device testing). In particular, we discuss the transition from laboratory-scale hydrogen evolution reaction (HER) catalyst measurements to those in single cells, which is a critical aspect crucial for scaling up from laboratory to industrial settings but often overlooked. Furthermore, we review the numerous catalyst design strategies deployed across the precious metal free HER literature. Subsequently, we showcase some of the most commonly investigated families of precious metal free HER catalysts; molybdenum disulfide-based, transition metal phosphides, and transition metal carbides for acidic electrolyte; nickel molybdenum and transition metal phosphides for alkaline. This includes a comprehensive analysis comparing the HER activity between several families of materials highlighting the recent stagnation with regards to enhancing the intrinsic activity of precious metal free hydrogen evolution reaction catalysts. Finally, we summarize future directions and provide recommendations for the field in this area of electrocatalysis.

Molybdenum oxide/nickel molybdenum oxide heterostructures hybridized active platinum co-catalyst toward superb-efficiency water splitting catalysis

A new catalyst has been developed that utilizes molybdenum oxide (MoO3)/nickel molybdenum oxide (NiMoO4) heterostructured nanorods coupled with Pt ultrafine nanoparticles for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) toward industrial-grade water splitting. This catalyst has been synthesized using a versatile approach and has shown to perform better than noble-metals catalysts, such as Pt/C and RuO2, at industrial-grade current level (≥1000 mA·cm−2). When used simultaneously as a cathode and anode, the proposed material yields 10 mA·cm−2 at a remarkably small cell voltage of 1.55 V and has shown extraordinary durability for over 50 h. Density functional theory (DFT) calculations have proved that the combination of MoO3 and NiMoO4 creates a metallic heterostructure with outstanding charge transfer ability. The DFT calculations have also shown that the excellent chemical coupling effect between the MoO3/NiMoO4 and Pt synergistically optimize the charge transfer capability and Gibbs free energies of intermediate species, leading to remarkably speeding up the reaction kinetics of water electrolysis.