Nickel Carbide Research Articles

Electrodeposition of Ni-WC composite coatings: formation, structure and properties

Currently, electroplating is actively developing, and one of its promising areas is the study of composite electrochemical coatings (CEC). They are of great interest to the industrial sector, especially for mechanical engineering, due to their unique properties. CEC contain microscopic particles as additives that can significantly improve coating properties such as hardness and wear resistance. This is especially important for the manufacturing of high-quality parts of industrial mechanisms. These areas can lead to new advances in the development of better and more durable materials. In this work, composite coatings of nickel-tungsten carbide were obtained by the method of electrodeposition. The deposition was carried out in a sulfuric acid electrolyte with different concentrations of tungsten carbide. Formation of composite coatings was carried out at a concentration of dispersed particles in a sulfate electrolyte of 10 g/L. The coatings have no pores or cracks. Nickel and tungsten carbide phases were detected in the coatings by X-ray phase and micro-X-ray spectral analyses. Inclusions of WC in the nickel matrix lead to an increase in the microhardness of the coating by 10–15 times. Wear resistance was assessed under dry sliding friction with reciprocating motion; a decrease in the volume of worn material by 2–3 times was noted when tungsten carbide was added into the nickel matrix.

Ni-based compounds in multiwalled graphitic shell for electrocatalytic oxygen evolution reactions

Here, we report a general strategy for designing a metal/carbon system, via a facile and environmentally friendly one-step approach, from metal acetate as an active electrocatalyst in oxygen evolution reaction (OER) during water decomposition. As a demonstration, a nanostructured Ni/C composite induced from nickel acetate is revealed in great detail. The resulting material is composed of: metallic nickel (Ni), nickel(II) oxide (NiO), and nickel carbide (Ni3C) coated with a graphitic shell and deposited on a carbon platform. Our findings underscore the prominent role of nickel species, including Ni0, Ni2+, and Ni3+, in driving the catalytic activity. Notably, the catalyst exhibits an overpotential of 170 mV, a Tafel slope of 49 mV·dec−1, an electrocatalytic surface area (ECSA) of 964.7 cm2, and a turnover frequency (TOF) value of 52.8 s−1, surpassing RuO2. The Raman spectra also suggest a graphitic "self-healing" phenomenon post-OER, attributed to the reduction of oxygen-containing groups. Carbon in the system (i) facilitates electron transfer, (ii) allows homogeneous distribution of Ni nanoparticles avoiding their agglomeration, and (iii) promotes durability of the electrocatalyst by serving as a protective barrier, shielding the core metal compounds. What is more, density functional theory (DFT) calculations allowed to optimized geometry of the model cluster Ni8O8(OH)8 describing two different sites on the β-NiOOH surface (001) and two different intermediates, (i)L-OOH and (ii)L-OOH. This facilitated to propose the reaction mechanisms involving both hydroxide ions and water molecules as reducers. Therefore, the chemisorption of OH− and H2O molecules at the NiOOH active center accompanied by bond breakage and the formation of a lattice hydroperoxide as an important intermediate is presumed. What is more, the proposed fabrication method for electroactive metal/carbon composites was validated with an iron and iron/nickel mixture.

Preparation of Ni-Cu-C composite catalysts prepared from mixed nickel and copper hydroxides for selective hydrogenation of 4-nitrophenol

A high-performance Ni-Cu-C composite catalyst was prepared from mixed nickel hydroxide and copper hydroxide, which were obtained by coprecipitation, by thermal treatment with acetylene-containing gas at 120 °C followed by hydrogen reduction at 180 °C. The characterization results of XRD, TEM, XPS, and H2-TPR measurements confirmed the presence of nickel carbide (Ni3C), copper carbide (CuxC), Cu, and Ni in the matrix of amorphous carbon in the composite catalyst. The mild preparation temperature and the porous carbon shell layers prevented the nano-sized particles from aggregation. The formation of interstitial Ni3C and CuxC significantly enhanced the dissociation of molecular hydrogen, accelerating the selective hydrogenation of 4-nitrophenol (4-NP) to yield 4-aminophenol (4-AP) at relatively mild conditions (80 °C and 1.0 MPa hydrogen pressure). The catalytic performance of the composite catalysts depended strongly on the Ni/Cu molar ratio, with an optimal Ni/Cu molar ratio of 4. In addition, the composite catalyst showed high conversion and selectivity to the corresponding aniline in the selective hydrogenation of other nitroarenes, including nitrobenzene, 4-nitrotoluene, 4-nitrochlorobenzene, 4-nitrobenzaldehyde, 4-nitroacetophenone, and 2-nitroaniline. The catalyst offers a novel approach to rational design and preparation of high-performance abundant metal catalysts for selective hydrogenation of nitroarenes.

Research on hydrogen distribution of electroless nickel plating on aluminum-based silicon carbide composites

Abstract Aluminum-based silicon carbide composite materials have the characteristics of high thermal conductivity, low thermal expansion, and good dimensional stability. Therefore, the composites are widely used in space microwave component shell products. In order to meet the functional requirements of conductivity, welding, and heat dissipation when applied to antenna microwave components, aluminum-based silicon carbide composite materials need to be chemically plated with nickel, which introduces hydrogen, thus requiring research on hydrogen release and control. Here, SEM, XRD, and other methods are used to characterize the microstructure of aluminum-based silicon carbide substrate and nickel plating layer. There are certain pore structures in both the substrate and plating layer, providing a place for hydrogen storage. The experimental method of hydrogen microprinting has been used to characterize the distribution of hydrogen. The results showed that the hydrogen distribution pattern in aluminum-based silicon carbide nickel plating is as follows: after nickel plating on aluminum-based silicon carbide, hydrogen is distributed in the nickel plating layer and the shallow substrate under the coating; with the extension of time, hydrogen spontaneously diffuses to the deep substrate; hydrogen is mainly distributed in the Al matrix and less on SiC particles.

Low-temperature sintering of SiC ceramics using a mixture of preceramic precursor and metal nanoparticles

Polymer infiltration and pyrolysis (PIP) has a limitation in increasing the relative density of SiC ceramics above 90 %. This is due to the blockage of open pore channels. In this study, a new process that incorporates Ni and graphite nanoparticles into SiC preceramic precursor is examined. Ni nanoparticles react with the SiC precursor to form low melting point nickel silicide phases which infiltrate into pores of the bulk without a blockage problem. In later infiltration cycles, graphite nanoparticles are added to convert the nickel silicide to nickel carbide and silicon carbide, which may prevent the deterioration of mechanical strength at high temperature. The relative density of SiC ceramics in this study increases to 92 % and above, which is higher than that of SiC ceramics prepared by the traditional PIP. The results of this study show a pathway to process high density SiC ceramics at relatively low sintering temperatures.

Kinetics and mechanisms of high-temperature oxidation in BCC and FCC high-alloy Fe-based alloys with high volume fraction of carbides

This study conducts a detailed analysis of high-temperature oxidation and microstructural evolution in two high-alloy Fe-based alloys, each characterized by a high-volume fraction of carbides but differentiated by their matrices − body-centered cubic (BCC) and face-centered cubic (FCC), which was achieved by the addition of nickel. By investigating the intricate interplay of factors such as phase composition, nickel content, and the presence of carbides, this research aims to elucidate the diverse oxidation kinetics and underlying mechanisms specific to each alloy type. Results show that the BCC alloy exhibits slower oxidation kinetics compared to its FCC counterpart, suggesting better performance in high-temperature environments. Moreover, while both alloys develop strong adhesive oxide scales primarily composed of Cr2O3, the FCC alloy experiences more pronounced scale spallation and cracking. A faster progression of decarburization was observed in the BCC alloy. This comprehensive comparison highlights how variations in matrix structure, along with nickel content and carbide behavior, critically influence oxidation kinetics, scale adhesion, and the overall integrity of oxide scales. Understanding these nuanced interactions is crucial for designing high-performance alloys tailored for extreme operating conditions.

Effect of High-Velocity Oxy-Fuel (HVOF) Tungsten Carbide Nickel (WC-Ni) Coating on the Fatigue Properties of Carbon Steel with Different Spraying Distances

Effect of High-Velocity Oxy-Fuel (HVOF) Tungsten Carbide Nickel (WC-Ni) Coating on the Fatigue Properties of Carbon Steel with Different Spraying Distances

A Novel Synthesis of Nickel Carbide Modified Glassy Carbon Electrode for Electrochemical Investigation of Archetypal Diabetes Biomarker in Human Serum and Urine Samples

We began with an exploration of a novel method for non-enzymatic glucose sensing through the direct electrochemical oxidation process using an annealed Nickel carbide (Ni3C) modified glassy carbon electrode (GCE). We cover the synthesis and detailed characterization of Ni3C, the modification process of the electrode, and its application in the electrocatalytic detection of glucose in human blood and urine samples. Ni3C, known for its high charge transfer efficiency, exceptional stability in harsh environments, and outstanding electrochemical activity, was prepared through an annealing method. The produced Ni3C, characterized by a nanoplate structure ranging from 20 to 50 nanometers, was applied to a GCE to benefit from its extensive surface area and structural robustness. Electrochemical impedance spectroscopy and cyclic voltammetry confirmed the superior electrocatalytic properties and charge transfer capabilities of Ni3C/GCE over the unmodified GCE. The glucose detection was achieved by the direct electrochemical oxidation of glucose on the modified electrode, showcasing a linear detection range from 0.05 to 2236 μM and an impressively low detection limit of 0.0186 μM. This research underscores the effectiveness of Ni3C/GCE as durable, efficient, and reliable tools for the non-enzymatic electrochemical sensing of glucose, providing new prospects for diabetes monitoring.

Comparative study of Ni-TaC composites via high-energy ball milling activation and spark plasma sintering: Reinforcement, densification, oxidation resistance, and mechanical property

In this study, metal matrix composites (MMCs) were produced using nickel (Ni) and tantalum carbide (TaC) powders by high-energy ball milling, and their structural characteristics and microstructural evolution against reinforcement interactions were investigated. The nominal compositions of the Ni-TaC composites were Ni (5, 10, 15, and 20) vol% TaC. The formation of the ductile-brittle (Ni-TaC) components was affected by the continued severe deformation caused by the high-energy ball milling. As a result, a Ni0.92Ta0.08 solid solution was formed, which influenced the lattice distortion and peak shift. The Ni-TaC composites were densely consolidated by spark plasma sintering at 900°C and 60 MPa. The effect of the TaC on the sinterability and mechanical properties of Ni-TaC composites was analyzed based on the shrinkage rate, densification strain, densification strain, uniform distribution of carbide phase in the Ni matrix, grain size, and morphology of crack propagation. Oxidation behavior was analyzed by scanning electron microscopy with energy dispersive X-ray diffraction. The results indicate that the formation of the NiO and TaO2 passive layer for Ni- 15 vol% TaC composites resulted in a 12 µm (thick) oxide layer. This was the thinnest oxide layer on surface at oxidation 1000°C.

Nickel Carbide Nanoparticle Catalyst for Selective Hydrogenation of Nitriles to Primary Amines.

Despite its unique physicochemical properties, the catalytic application of nickel carbide (Ni3 C) in organic synthesis is rare. In this study, we report well-defined nanocrystalline Ni3 C (nano-Ni3 C) as a highly active catalyst for the selective hydrogenation of nitriles to primary amines. The activity of the aluminum-oxide-supported nano-Ni3 C (nano-Ni3 C/Al2 O3 ) catalyst surpasses that of Ni nanoparticles. Various aromatic and aliphatic nitriles and dinitriles were successfully converted to the corresponding primary amines under mild conditions (1 bar H2 pressure). Furthermore, the nano-Ni3 C/Al2 O3 catalyst was reusable and applicable to gram-scale experiments. Density functional theory calculations suggest the formation of polar hydrogen species on the nano-Ni3 C surface, which were attributed to the high activity of nano-Ni3 C towards nitrile hydrogenation. This study demonstrates the utility of metal carbides as a new class of catalysts for liquid-phase organic reactions.

Electrochemically decoupled reduction of CO2 to formate over a dispersed heterogeneous bismuth catalyst enabled via redox mediators.

Electrochemical CO2 reduction is a topic of major interest in contemporary research as an approach to use renewably-derived electricity to synthesise useful hydrocarbons from waste CO2. Various strategies have been developed to optimise this challenging reaction at electrode interfaces, but to-date, decoupled electrolysis has not been demonstrated for the reduction of CO2. Decoupled electrolysis aims to use electrochemically-derived charged redox mediators - electrical charge and potential vectors - to separate catalytic product formation from the electrode surface. Utilising an electrochemically generated highly reducing redox mediator; chromium propanediamine tetraacetate, we report the first successful application of decoupled electrolysis to electrochemical CO2 reduction. A study of metals and metal composites found formate to be the most accessible product, with bismuth metal giving the highest selectivity. Copper, tin, gold, nickel and molybdenum carbide heterogeneous catalysts were also investigated, in which cases H2 was found to be the major product, with minor yields of two-electron CO2 reduction products. Subsequent optimisation of the bismuth catalyst achieved a high formate selectivity of 85%. This method represents a radical new approach to CO2 electrolysis, which may be coupled directly with renewable energy storage technology and green electricity.

The influence of spark plasma sintering on multiscale mechanical properties of nickel-based composite materials

The paper presents a comprehensive investigation of the influence of the main process parameters of spark plasma sintering on the mechanical and microstructural properties of nickel-silicon carbide composites at various scales. Microstructure analysis performed by scanning and transmission electron microscopy revealed a significant interfacial reaction between nickel and silicon carbide due to the decomposition of silicon carbide. The chemical interaction of the matrix and reinforcement results in the formation of a multicomponent interphase zone formed by silicides (Ni31Si12 or/and Ni3Si) and graphite precipitates. Furthermore, several types of structure defects were observed (mainly nano/micropores at the phase boundaries). These significantly influenced the mechanical response of nickel-silicon carbide composites at different levels. At the macroscopic scale, uniaxial tensile tests confirmed that applying a 1000 °C sintering temperature ensured that the manufactured composite was characterised by satisfactory tensile strength, however, with a considerable reduction of material elongation compared to pure nickel. Moreover, the fractography study allowed us to identify a significant difference in the damage mode for certain nickel-silicon carbide samples. Secondly, the interface of the nickel matrix and silicate interphase was tested by bending with microcantilevers to evaluate its deformation behaviour, strength, and fracture characteristics. It was confirmed that a diffusive kind of interface, such as Ni-NiSi, demonstrates unexpected bonding properties with a relatively large range of plastic deformation. Finally, the nanoindentation of three main components of the nickel-silicon carbide composite was executed to evaluate the evolution of nanohardness, Young's modulus, and elastic recovery due to the application of various spark plasma sintering conditions.

Structure, Phase Composition, and Hardness of Ni3Al–TiC Composite Fabricated by Thermal Explosion of Nickel, Aluminum, and Titanium Carbide Powder Mixture

Structure, Phase Composition, and Hardness of Ni3Al–TiC Composite Fabricated by Thermal Explosion of Nickel, Aluminum, and Titanium Carbide Powder Mixture

Nanoparticulate WN/Ni3C Coupling in Ceramic Coatings for Boosted Urea Electro‐Oxidation

AbstractUrea electrolysis can convert urea from urea‐rich wastewater to hydrogen for environmental protection and sustainable energy production. However, the sluggish kinetics of urea oxidation reaction (UOR) requires valence‐variable sites that are generally active at high anodic overpotentials. Herein, a robust ceramic coating is constructed with coupled tungsten nitride (WN)/nickel carbide (Ni3C) nanoparticles to achieve valence‐stable catalytic sites with outstanding UOR performance. Various characterization results indicate strong interfacial electron transfer from WN to Ni3C in coupled nanoparticles, which enables reservation of Ni2+ sites without self‐oxidation during UOR, quite distinct from the kinetically slow Ni3+OOH‐catalyzed UOR pathway. Theoretical calculations show that the coupled effect in WN/Ni3C leads to enhanced electron transfer from catalytic sites to adsorbed urea, and W sites are thermodynamically favorable for UOR. This efficiently lowers the barrier of rate‐determining step (RDS: *CO‐N2 → *CO·OH), thus enabling fast UOR kinetics and a low potential of 1.336 V at 100 mA cm−2, which identifies this ceramic coating as one of the best UOR electrocatalysts. This work opens a new avenue for design of stable and active sites in ceramics coatings toward advanced electrocatalytic applications.

Thermal Conversion of Nanocrystalline Metal Hydroxide Salts to Metal Carbides, Pnictides, Chalcogenides, and Halides.

A general procedure for synthesizing various inorganic compounds in a similar manner is required in the field of material chemistry. The use of solid-state reactive agents with inorganic precursors is a successful approach in this direction. In this study, organic-inorganic hybrid metal hydroxide salts (MHSs) were utilized to synthesize various inorganic compounds by a simple heat treatment method because they can be assumed to be "premixed" inorganic precursors and solid-state reactive agents. Comparative studies revealed that the nanocrystalline characteristics and coordination of the carboxylate of the synthesized MHSs enabled simultaneous dehydration of hydroxides and decomposition of carboxylates and subsequent formation of metals and metal sulfides. Manganese, iron, cobalt, nickel, and zinc sulfides, as well as nickel carbides, pnictides, chalcogenides, and halides were obtained using the same procedure. We believe that using nanocrystalline organic-inorganic hybrid MHSs as both inorganic precursors and organic reactive agents will be a simple and versatile way to prepare a wide variety of inorganic complex compounds.

Heterogeneous MgO-modified Ni3Sn cermet anode for hydrocarbon-fueled solid oxide fuel cells

To achieve the commercial application of solid oxide fuel cells (SOFCs), the performance degradation of the cell caused by carbon deposition needs to be well addressed. Here we report a new anode with nanostructured heterogeneous interfaces by integrating 0.38 wt% Sn and 0.19 wt% MgO into NiSDC for hydrocarbon-fueled SOFCs. The cell with 0.38Sn–0.19MgONiSDC anode exhibits a peak power density of 374 mW cm−2 and excellent long-term stability for 100 h with a power attenuation about 13.5% in humidified methane at 700 °C, which is attributed to the decreased rate of carbon deposition by promoting the formation of CO bonds instead of CC bonds, increasing the activation barrier for methane cracking and preventing the formation of nickel carbides by the confinement effect of heterogeneous catalysts, and the enhanced rate of carbon removal is attributed to excellent hydrophilicity and adsorption of CO2, as revealed by combined density function theory (DFT) calculations and experimental characterizations. This finding offers potential for the application of hydrocarbon-fueled SOFCs and provides a guide for designing coking-tolerant anodes.

The Effect of Support on Catalytic Performance of Ni-Doped Mo Carbide Catalysts in 2-Methylfuran Production

Ni-doped Mo carbide with Ni/Mo atomic ratio of 0.1 was supported on SiO2, Al2O3, and a porous carbon material (C), using a combination of gel combustion and impregnation methods. XRD, XPS, XANES, and EXAFS analyses indicated that the main active sites for the supported catalysts were metallic nickel and Mo carbides. The catalysts were evaluated in furfural hydrogenation to produce 2-methylfuran (2-MF) in a batch reactor at 150 °C under a hydrogen pressure of 6.0 MPa. The carbide materials supported on C showed the highest activity and selectivity towards 2-MF formation, with a yield of 61 mol.% after 3.5 h. Using furfuryl alcohol as the feedstock instead of furfural resulted in a high selectivity to 2-MF production. The carbon-supported sample was tested in a fixed-bed reactor at 160–260 °C with a pressure of 5.0 MPa in the hydrogenation of furfuryl alcohol, leading to the formation of up to 82 mol.% of 2-MF at 160–200 °C. The higher temperature (260 °C) resulted in the formation of C5 alcohols and hydrocarbons, while the hydrogenation of furfural at the same temperature led to 100 mol.% conversion, and up to an 86 mol.% yield of 2-MF.

Activity Origin of the Nickel Cluster on TiC Support for Nonoxidative Methane Conversion.

Designing an active and selective catalyst for nonoxidative conversion of methane under mild conditions is critical for natural gas utilization as a chemical feedstock. Here, we demonstrate that the origin of the selective nonoxidative conversion of methane by the titanium carbide supported nickel cluster arises from the formation of a nickel carbide site under the reaction conditions, which could stabilize the CHx intermediate to facilitate the C-C coupling, but further coking is rather limited. The reaction mechanism reveals that the C2 products can be formed via a key -CHx-CH3 intermediate. In addition, we demonstrate that boration of the nickel cluster site can improve the methane conversion toward C2 products. That higher activity and selectivity from the moderate rise in d orbital energy levels can therefore be considered as a descriptor of the catalyst effectiveness. These findings provide an understanding of the dynamic behavior of the single nickel cluster toward methane conversion to C2 products and guidance for their future rational design.

Properties and Microstructure Evaluation in NiAl-xWC (x = 0 − 90 wt.%) Intermetallic-Based Composites Prepared by Mechanical Alloying

In this work, NiAl-xWC (x = 0 - 90 wt.% WC) intermetallic-based composites were successfully synthesized by mechanical alloying (MA) and a hot-pressing approach. As initial powders, a mixture of nickel, aluminum and tungsten carbide was used. The phase changes in analyzed systems after mechanical alloying and hot pressing were evaluated by an X-ray diffraction method. Scanning electron microscopy and hardness test examination were used for evaluating microstructure and properties for all fabricated systems from the initial powder to the final sinter stage. The basic sinter properties were evaluated to estimate their relative densities. Synthesized and fabricated NiAl-xWC composites showed an interesting relationship between the structure of the constituting phases, analyzed by planimetric and structural methods and sintering temperature. The analyzed relationship proves that the structural order reconstructed by sintering strongly depends on the initial formulation and its decomposition after MA processing. The results confirm that it is possible to obtain an intermetallic NiAl phase after 10 h of MA. For processed powder mixtures, the results showed that increased WC content intensifies fragmentation and structural disintegration. The final structure of the sinters fabricated in lower (800 °C) and higher temperature regimes (1100 °C), consisted of recrystallized NiAl and WC phases. The macro hardness of sinters obtained at 1100 °C increased from 409 HV (NiAl) to 1800 HV (NiAl + 90% WC). Obtained results reveal a new applicable perspective in the field of intermetallic-based composites and remain highly anticipated for possible application in severe-wear or high-temperature conditions.

State of the Surface During CO Hydrogenation over Ni(111) and Ni(211) Probed by Operando X-ray Photoelectron Spectroscopy

The state of the surface near-region during CO hydrogenation of Ni(111) and Ni(211) single crystal surfaces was investigated using various gas mixtures between 150 and 500 mbar, 200 and 325 °C, by operando X-ray photoelectron spectroscopy. We report how higher temperatures and hydrogen content correlate with a movement of CO away from the on-top configurations and toward multicoordinated sites of the nickel surface and how a nickel carbide is formed in the surface near region, particularly at high partial pressures of CO and lower temperatures. The presence of the carbide affects the CO bonding and was observed to be reduced during hydrogen-rich conditions and temperatures above 250 °C.