Nickel Carbide Research Articles

An analytical investigation pertaining to autocatalytic plating of chromium nickel carbide powder on copper alloys using electroless deposition method

An analytical investigation pertaining to autocatalytic plating of chromium nickel carbide powder on copper alloys using electroless deposition method

An analytical investigation pertaining to autocatalytic plating of chromium nickel carbide powder on copper alloys using electroless deposition method

Engineered components can gain desirable properties when coated with surface materials. Hard chromium has been given priority in material selection list while making choice for certain wear and corrosion- resistant coatings because of its desirable combination of chemical resistance, adhesion, and mechanical properties. Owing to the existing environmental safety concerns, there is restrictions on the employability of hexavalent chromium ions as plating material. This substantiates a need to develop an environmentally friendly process for alternative coatings. Today, Chromium Nickel Carbide (Cr-Ni-C) is emerging as good quality plating substrate with no the toxic compounds as compared to existing chromium complex. The purpose of this research paper is to investigate electroless processes for plating metal powder, chromium nickel carbide with nickel. These particles were successfully encapsulated with Ni by electroless deposition method using different solutions.

Microstructure and Tribo-corrosion Behavior of Stainless Steel-304 Cladding with the Mixture of Nickel and Chromium Carbide by Microwave Energy

Microstructure and Tribo-corrosion Behavior of Stainless Steel-304 Cladding with the Mixture of Nickel and Chromium Carbide by Microwave Energy

Ni, Co and Ni-Co-Modified Tungsten Carbides Obtained by an Electric Arc Method as Dry Reforming Catalysts

Dry reforming of methane (DRM), to produce synthesis gas, is one of the most important chemical reactions used for the industrial production of hydrogen and leads to the synthesis of hydrocarbons (liquid fuels) and other valuable products. A cost-effective alternative to active and stable noble metal DRM catalysts, with comparable catalytic performance, can be composite materials based on nickel, cobalt and transition metal carbides. In this line, the present work proposes a non-standard way to obtain dry reforming catalysts of Ni, Co and Ni-Co-modified tungsten carbide (WC) produced by an electric arc method. Different amounts of nickel, cobalt and their mixtures were deposited on tungsten carbide by deposition-precipitation with NaOH (DP) and incipient wetness impregnation (IWI) methods. The resulting materials were characterized by N2 adsorption-desorption, transmission electron microscopy, energy dispersive spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy, and their performance was evaluated in DRM. The composition and preparation method of catalysts predetermined their structural, textural and electronic properties, playing a decisive role in their activity for DRM. DP-prepared 20%Ni/WC material remained resistant to oxidation, both that of the active metal (nickel) and of the tungsten carbide, as well as to coking during DRM. This sample proved to be the most active and stable among all studied materials. Possibly, the resistance to oxidation and coking was due to a more efficient implementation of the oxidation/(re)carbonization cycle on the surface of this catalyst.

Facile Synthesis of Amorphous NiO/Reduced Graphene Oxide as a Cocatalyst for Enhanced Dye-Sensitized Photocatalytic H2 Evolution

It is still a challenge to develop efficient catalysts for hydrogen evolution reaction (HER) via a low-cost and simple method. Herein, we report an amorphous NiO/reduced graphene oxide (A-NG) composite as a cocatalyst for enhanced photocatalytic H2 evolution via dye sensitization. The A-NG composite is facilely fabricated by calcinating the NiCl2/GO precursor at a low temperature of 250 °C. The detailed characterizations show that amorphous NiO presents as tiny nanoparticles highly dispersed on graphene sheets, and nickel carbide is formed at the NiO/graphene interface, which demonstrates the strong interaction between Ni and the defective carbon of graphene. Compared with crystalline NiO/rGO (C-NG), the A-NG cocatalyst shows much enhanced dye-sensitized photocatalytic HER activity because the amorphous NiO nanoparticles can effectively adsorb the dye. As a result, highly dispersed amorphous NiO accelerates the photoinduced electron transfer from the excited dye to the cocatalyst, namely, the amorphous nickel carbide formed between NiO and rGO. This work provides a low-cost and simple method to develop efficient cocatalysts for photocatalytic H2 evolution.

2D transitional-metal nickel compounds monolayer: Highly efficient multifunctional electrocatalysts for the HER, OER and ORR

The atomically dispersed Ni metal on two-dimensional (2D) monolayer species have exhibited impressive catalytic properties towards oxygen evolution and oxygen reduction reactions (OER/ORR). In this work, nickel boride and nickel carbide monolayers, which is inspired by the more different active sites of monolayer surface, such as Ni atom, that efficiently catalyze the reduction of OOH to O2 to some extent, while B/C atom can work in the reduction of H∗ to H2, are theoretically reported. Remarkably, the density functional theory (DFT) calculations showed that the random combination of Ni atom to two free-metal atoms such as B and C to form catalytically active double sites lead to a remarkable reduction of the first or last hydrogenation free energy barrier step. The resulting Ni2B5 and NiC3 exhibited ultra-low Gibbs free energy (ΔGH∗) of only 0.096 V and 0.018 V for HER and lower onset potentials of only 0.39 V (0.62 V) and 0.60 V (0.31 V) for OER (ORR), respectively, while the NiB6 exhibited appropriate OER and ORR electrocatalytic activity. The superior bifunctional even multifunctional catalytic performance in the overall water splitting is mainly attributed to both the electron donation from the Ni metal atoms to the key intermediates, which significantly polarizes and weakens the O–H bond, and to the synergistic effect of the B/C atoms that moderates the binding strength of terminal top of H atoms. This work constitutes the DFT study of the water electroreduction processes on diverse nickel compounds monolayer catalytic sites and, consequently, paves the way towards the rational design of highly efficient bifunctional even multifunctional electrocatalysts.

Tailoring the adsorption behavior of superoxide intermediates on nickel carbide enables high-rate Li–O2 batteries

Probing the relationship between the adsorption of superoxide species and the kinetics of Li–O2 chemistry is critical for designing superior oxygen electrodes for the Li–O2 battery, yet the modulation essence, especially at the atomic level, remains little understood. Herein, we reveal that the adsorption behaviors of superoxide species can be effectively regulated via a core-induced interfacial charge interaction, and we find that moderate adsorption strength can enable superior rate capability in a Li–O2 battery. More importantly, operando X-ray absorption near-edge structure and surface-enhanced Raman spectroscopy provide tools to monitor in situ the evolution of the superoxide intermediates and the electronic states of the catalyst's metal sites during the discharge and charge processes, and correlate these with the surface adsorption states. The concept of tuning adsorption behavior through interfacial charge engineering could open up new opportunities to further advance the development of the Li–O2 battery and beyond.

Synergistic catalytic enhancement of metal-organic framework derived nanoarchitectures decorated on graphene as a high-efficiency bifunctional electrocatalyst for methanol oxidation and oxygen reduction

Designing highly efficient, long-lasting, and cost-effective cathodic and anodic functional materials as a bifunctional electrocatalyst is essential for overcoming the bottleneck in fuel cell development. Herein, a novel two-step synthesis strategy is developed to synthesize metal-organic framework (MOF) derived nitrogen-doped carbon (NC) with improved spatial isolation and a higher loading amount of cobalt (Co) and nickel carbide (Ni3C) nanocrystal decorated on graphene (denoted as Co@NC-Ni3C/G). Benefiting from multiple active sites of high N-doping level, uniform dispersion of Co and Ni3C nanocrystals, and a large active area of graphene, the Co@NC-Ni3C/G hybrids exhibit excellent methanol oxidation reaction (MOR) and oxygen reduction reaction (ORR) efficiency in an alkaline environment. For MOR, the optimized Co@NC-Ni3C/G-350 catalyst achieved a current density of 44.8 mA cm−2 at an applied potential of 1.47 V (V vs. RHE), which is significantly higher than Co@NC-Ni3C (42.07 mA cm−2) and Co@NC (24.1 mA cm−2) in 0.5 M methanol + 1.0 M KOH solutions. In addition, during the CO retention test, the Co@NC-Ni3C/G-350 catalyst exhibits excellent CO tolerance capacity. Excitingly, the as-prepared Co@NC-Ni3C/G-350 hybrid exhibits significantly improved ORR catalytic efficiency in terms of positive onset and half-wave potential (Eonset = 0.90 V, E1/2 = 0.830 V vs. RHE), small Tafel slope (34 mV dec−1) and excellent durability (only reduced 0.016 V after 5000 s test). This work provides new insights into MOF-derived functional nanomaterials for anode and cathode co-catalysts for methanol fuel cells.

Tracing the Active Phase and Dynamics for Carbon Nanofiber Growth on Nickel Catalyst Using Environmental Transmission Electron Microscopy.

Benefitting from outstanding ability of CC reforming and hydrogen activation, nickel is widely applied for heterogeneous catalysis or producing high-quality carbon structures. This high activity simultaneously induces uncontrollable carbon formation, known as coking. However, the activity origin for growing carbon species remains in debate between the on metallic facets induction and nickel carbide segregation. Herein, carbon growth on Ni catalyst is tracked via in situ microscopy methods. Evidence derived from high-resolution transmission electron microscopy imaging, diffraction, and energy loss spectroscopy unambiguously identifies Ni3 C as the active phase, as opposed to metallic Ni nickel or surface carbides as traditionally believed. Specifically, Ni3 C particle grows carbon nanofibers (CNF) layer-by-layer through synchronized oscillation of tip stretch and atomic step fluctuations. There is an anisotropic stress distribution in Ni3 C that provides the lifting force during nanofiber growth. Density functional theory computations show that it is thermodynamically favorable for Ni3 C to decompose into Ni and surface-adsorbed carbon. Carbonaceous deposits aggregate asymmetrically round the particle because partial surface is exposed to the hydrocarbon environment whereas the bottom side is shielded by the support. This induces a carbon concentration gradient within the particle, which drives C migration through Ni3 C phase before it exits as CNF growth.

Boosting oxygen evolution reaction of hierarchical spongy NiFe-PBA/Ni3C(B) electrocatalyst: Interfacial engineering with matchable structure

Rational interfacial structure with excellent charge transfer and exposure of numerous active sites plays vital roles in heterogeneous catalysis. Herein, a hierarchical spongy electrocatalyst with active NiFe Prussian blue analogues and nickel carbides interface (NiFe-PBA/Ni3C(B)) is proposed and fabricated by a borate-assisted strategy. The unique structure and matchable interface benefit from the desorption of borate ligands in-situ during the pyrolysis and carbonization process. The optimal electrocatalyst composing of metal–organic framework (NiFe prussian blue analogues) in conjunction with a metallic transition carbide phase (nickel carbide) exhibits an ultra-low overpotential of only 196 mV at 10 mA cm−2 and a small Tafel slope of 30.1 mV dec-1 for OER in KOH. The robust water oxidation performance can be ascribed to the abundant adsorption sites and effective interfacial interaction. In addition, computational simulations further confirm that NiFe-PBA/Ni3C(B) is favorable for OER since the optimized electronic distribution and metal-3d orbitals interact around Fermi level at the interface. This research provides a new insight into rationally designing efficient electrocatalysts via morphology engineering and integrating different functional phase with complementary advantages for catalysis application.

A Self-Reconstructed Bifunctional Electrocatalyst of Pseudo-Amorphous Nickel Carbide @ Iron Oxide Network for Seawater Splitting.

Here, a sol‐gel method is used to prepare a Prussian blue analogue (NiFe‐PBA) precursor with a 2D network, which is further annealed to an Fe3O4/NiCx composite (NiFe‐PBA‐gel‐cal), inheriting the ultrahigh specific surface area of the parent structure. When the composite is used as both anode and cathode catalyst for overall water splitting, it requires low voltages of 1.57 and 1.66 V to provide a current density of 100 mA cm−2 in alkaline freshwater and simulated seawater, respectively, exhibiting no obvious attenuation over a 50 h test. Operando Raman spectroscopy and X‐ray photoelectron spectroscopy indicate that NiOOH2–x active species containing high‐valence Ni3+/Ni4+ are in situ generated from NiCx during the water oxidation. Density functional theory calculations combined with ligand field theory reveal that the role of high valence states of Ni is to trigger the production of localized O 2p electron holes, acting as electrophilic centers for the activation of redox reactions for oxygen evolution reaction. After hydrogen evolution reaction, a series of ex situ and in situ investigations indicate the reduction from Fe3+ to Fe2+ and the evolution of Ni(OH)2 are the origin of the high activity.

A “Fraternal Twin” atomic layer deposition process for nickel carboxylate and nickel carbide

In this study, a “fraternal twin” atomic layer deposition process for nickel carboxylate (130–160 °C) and nickel carbide (260–290 °C) was reported with the growth rate of 1.2 Å/cycle and 0.8 Å/cycle, respectively. Ni(acac)2·(tmeda) and formic acid were employed as precursors. The materials were characterized by SEM, XRD, FTIR and XPS. In addition, their formation mechanisms were also investigated.

Elucidating the promoting role of Mo2C in methane activation using Ni-xMo2C/FAU to catalyze methane steam reforming

We report the synthesis and characterization, reaction kinetics, and deactivation mechanism of a series of catalysts with metallic nickel (Ni) and molybdenum carbide (Mo2C) particles supported on zeolite Y (Ni-Mo2C/FAU) in methane steam reforming (MSR) reaction at 850 °C. Despite a low Ni loading of 2.4 wt%, MSR on Ni-Mo2C/FAU exhibits high activity and stability, yet deactivation of Ni-FAU is significant. Further investigations elucidate that the catalyst deactivation is caused by Ni particle sintering via Ostwald ripening instead of coking, and steam induces hydroxylated Ni surface that accelerates sintering. Moreover, Mo2C boosts the activity and stability of Ni on zeolite Y by enhancing CH4 activation rather than activating H2O. The interplays among Mo2C and Ni particles dynamically balance the carbon formation and consumption rates, and inhibit Ni sintering. This study demonstrates that high MSR activity and stability can be achieved on transition metal carbide – Ni catalysts with systematically tuned compositional, structural, and interfacial factors.

Epitaxial Growth of Ultrathin Highly Crystalline Pt-Ni Nanostructure on a Metal Carbide Template for Efficient Oxygen Reduction Reaction.

Structure engineering strategies such as core-shell and hollow nanostructures are effective pathways to improve the utilization of noble metals for catalysis. However, nowadays materials design based on these strategies still largely rely on precious metal templates. Herein, the epitaxial growth of highly crystalline Pt3 Ni overlayer on earth-abundant nickel carbide is reported, forming Ni3 C@Pt3 Ni core-shell nanoparticles with a well-defined interface through a new lattice-match-directed synthetic strategy. Derived from such core-shell nanostructures, ultrathin highly crystalline Pt3 Ni nanocages have an advantageous configuration of oxygen reduction reaction (ORR)-favored facets and inherently high active surface area for the ORR, bringing high mass activity and specific activity as much as 4.71AmgPt -1 and 5.14mAcm-2 , which are 26 and 20 times to that of commercial Pt/C, respectively. This novel epitaxial growth of platinum opens up new avenues to rationally design highly active and economical electrocatalysts.

High temperature (900 °C) sliding wear of CrNiAlCY coatings deposited by high velocity oxy fuel thermal spray

Nickel based superalloy are in demand for high temperature applications and their corrosion, erosion and wear resistance have been investigated for a long time. Nickel chromium (NiCr) alloys are widely used for corrosion resistant coatings, while chromium carbide nickel chromium (CrC-NiCr) alloys are preferred for wear resistant coatings at high temperature. In this study CrNiAlCY coatings were deposited via a liquid fuelled high velocity oxy fuel (HVOF) thermal spray using two spray parameters and tested as wear resistant coatings. Effects of processing parameters on microstructure and mechanical properties of the coatings were investigated. Results showed that higher oxygen flow rates are critical for obtaining coatings with lower porosity and higher microhardness. Coating with lower porosity and higher hardness was chosen for both room temperature (~24 °C) and high temperature (900 °C) unlubricated sliding wear tests in a ball on disc setup. The coating was tested against alumina counterbody under 3 different loading conditions (10, 30 and 60 N). The wear rate of the coating was directly proportional to the applied load at room temperature. In the room temperature tests, wear debris was produced, which then oxidised and pushed away to the edges of the wear track. On the other hand, wear debris was smeared on the wear surface at high temperature tests. The surface was oxidised into Cr 2 O 3 at high temperatures, which acted as a protective layer. Although thermal softening took place at higher temperatures, wear rates under 10 and 30 N were similar to room temperature values due to the protective oxide layer formed on the top surface; however, the oxide layer under 60 N could not withstand the load, started to crack and lost its protective ability. • CrNiAlCY coatings have been produced using a liquid-fuelled HVOF thermal spray. • Effects of spray parameters on the microstructure and hardness studied. • Wear performance was investigated against the alumina counter body. • 2 Different temperature settings were used during the wear tests.

Features of cubic Ni3C and NiC carbides obtained by HT-HP sintering

In this work NiC carbides were manufactured by HP-HT sintering of mechanically alloyed charges of the elemental Ni–carbon nanotubes (CNT) or Ni–Graphite. Structural features of the materials obtained were characterized by X-ray diffraction and scanning electron microscopy. X-ray diffraction studies have revealed that the crystal lattice of nickel carbide obtained from mechanically alloyed Ni–CNT charge is supplemented with additional Carbon atoms from the graphite shell of the high-pressure cell at HT-HP sintering. On the other hand, nickel carbide fabricated from mechanically alloyed Ni–Graphite charge retains its composition. It is shown that materials studied in this work demonstrate an advanced value of microhardness (up to 7 GPa).

Increased wear resistance of subsoiler bits

Purpose. Improve wear resistance of subsoiler bits by coating with new wear-resistant materials. Methods. Graphic, micrometer, comparative and field tests of locally hardened experimental parts of tillage machines. Results. A technology has been developed for restoring and strengthening subsoiler bits using new wear-resistant materials. Conclusions 1. According to the results of laboratory comparative tests of samples of wear-resistant materials deposited by detonation and plasma methods, compression sintering and surfacing, it was found that materials made of tungsten carbides Kutrite Carbide size and VK-8 have the highest relative wear resistance, respectively, 96.15 and 50 times higher, compared with hardened steel 65G, and titanium, chromium and nickel carbides – 54.34 times higher. 2. Based on the results of a production inspection of a batch of restored and strengthened deep-rippers bits in the soil conditions of UPI-AGRO LLC, it was found that the operating time of experimental deep-rippers bits is at the level of original parts and their resource is about 480 hectares per TG Gaspardo Artiglio R17820721 unit and 240 hectares on the Dante Macchine unit. Keywords: hardening, wear resistance, subsoiler bits.

Nickel carbide (Ni3C) nanoparticles for catalytic hydrogenation of model compounds in solvent

Nickel carbide nanoparticles (Ni3C) synthesized in high-boiling point solvent are used as colloidal catalysts for the hydrogenation of polar groups and hydrocarbons. They are stable under operating conditions (100 °C, 7 bar H2).

Photoelectron velocity-map imaging spectroscopy of nickel carbide: examination of the low-lying electronic states

Ground-state NiC is better described as involving one electron-sharing σ bond, one electron-sharing π bond, and one dative π bond.

Theoretical study of the Ni–C system in the pressure range of 0–100 GPa

This work is devoted to the search for stable compounds and structures in the Ni–C system in the pressure range of 0–100 GPa. Based on the density functional theory, a search for stable compounds and structures in the Ni–C system was carried out using modern algorithms for predicting crystal structures. As a result, one stable intermediate compound Ni3C with the structure of cementite, previously synthesized at 184 GPa, was revealed. Ni3C nickel carbide is dynamically stable, which is confirmed by the absence of imaginary modes in the phonon spectra. According to the results obtained, Ni3C is formed by the reaction of 3Ni + C ↔ Ni3Cabove 23 GPa and is stable up to at least 100 GPa. Spin-polarized calculations showed that the Ni3C has no magnetic moment in the entire pressure range. For carbon-rich compounds, performed calculations on the crystal structure prediction did not reveal any phase that would be energetically favorable relative to amixture of pure nickel and carbon. Also, it was shown that the most energetically favorable modification of metastable carbide Ni7C3 is orthorhombic Ni7C3-Pbca.