Ni Metal Research Articles

Novel Ni(II) and Zn(II) Schiff base metal chelates as promising DNA binder, Antioxidant and Antifungal agents

<p>Schiff base ligands and their 3d-metal chelates have gained significant attention due to various applications in various scientific platforms. Due to their chelating propensity, they possess a wide range of biological, biochemical, catalytic, clinical, dying, and pharmacological properties.<strong> </strong>Here, in present studies,<strong> </strong>two novel Ni(II) and Zn(II) transition metal chelates have been synthesized by condensing their metal salts with Schiff base ligand 4-chloro-2-(2,5-dimethoxybenzylideneamino)-5-nitrophenol<strong> </strong>originated from 2,5-dimethoxybenzaldehyde and 2-amino-4-chloro-5-nitrophenol. The synthesized Schiff base ligand and its metal chelates have been Spectro-chemically examined by FT-IR, UV-Vis absorption spectroscopy, Mass Spectrometry, <sup>1</sup>HNMR, Thermogravimetric analysis (TGA) and Powdered-XRD. These compounds are biologically reactive and exhibit antifungal, antioxidant, and DNA-binding activity. The Ni(II) metal chelate gives better biological activity than the Zn(II) metal chelate and parent Schiff base ligand.</p>

Boosting Urea-Assisted Natural Seawater Electrolysis in 3D Leaf-Like Metal-Organic Framework Nanosheet Arrays Using Metal Node Engineering.

Metal node engineering, which can optimize the electronic structure and modulate the composition of poor electrically conductive metal-organic frameworks, is of great interest for electrochemical natural seawater splitting. However, the mechanism underlying the influence of mixed-metal nodes on electrocatalytic activities is still ambiguous. Herein, a strategic design is comprehensively demonstrated in which mixed Ni and Co metal redox-active centers are uniformly distributed within NH2-Fe-MIL-101 to obtain a synergistic effect for the overall enhancement of electrocatalytic activities. Three-dimensional mixed metallic MOF nanosheet arrays, consisting of three different metal nodes, were in situ grown on Ni foam as a highly active and stable bifunctional catalyst for urea-assisted natural seawater splitting. A well-defined NH2-NiCoFe-MIL-101 reaches 1.5 A cm-2 at 360 mV for the oxygen evolution reaction (OER) and 0.6 A cm-2 at 295 mV for the hydrogen evolution reaction (HER) in freshwater, substantially higher than its bimetallic and monometallic counterparts. Moreover, the bifunctional NH2-NiCoFe-MIL-101 electrode exhibits eminent catalytic activity and stability in natural seawater-based electrolytes. Impressively, the two-electrode urea-assisted alkaline natural seawater electrolysis cell based on NH2-NiCoFe-MIL-101 needs only 1.56 mV to yield 100 mA cm-2, much lower than 1.78 V for alkaline natural seawater electrolysis cells and exhibits superior long-term stability at a current density of 80 mA cm-2 for 80 h.

Highly dispersed nickel-copper bimetallic catalysts prepared by monolayer NiCu-layered double hydroxide nanocomposites for CO2 electrocatalytic reduction

The design of novel electrocatalyst for CO2 reduction reaction to available chemical substance is a meaningful approach to mitigate the CO2 emission problem. However, it is challenging to achieve uniform dispersion of the metals in the carbon substrate to enhance catalytic performance. Surprisingly, layered double hydroxide nanosheets have uniform metal distribution, which are appropriate metal negative supports for CO2RR catalyst. Herein, we have successfully prepared a simple, green and efficient novel CO2RR metal catalyst using monolayer NiCu-LDH nanocomposites as precursor. Based on solid phase exfoliation, monolayer NiCu-LDH nanocomposite material was obtained, and then the ultra-thin two-dimensional carbon substrate with homogeneous metals dispersion was formed by in-situ nitridation. The obtained Ni2Cu1-CN shows excellent CO2RR performance with CO current density of 12.65 mA cm−2 and great CO faraday efficiency of 96.9 % at −0.8 V (vs. RHE). But metals formed nanoparticles due to vibration migration at high temperature, which caused active sites to be obscured. Surprisingly, introduction of Zn prevented Cu and Ni metals from agglomerating and exposed more active sites. The as‐prepared Ni2Cu1Zn1-CN shows excellent catalytic performance with the greatest CO faraday efficiency of 98.1 % and high CO current density of 16.6 mA cm−2 at −0.8 V (vs RHE) and remarkable stability.

Recent Advances in Denitrogenative Organic Transformations of 1,2,3‐Benzotriazin‐4(3H)‐ones

AbstractDenitrogenative organic transformations and related reactions are a class of significant approaches for carrying out unusual C−C/C‐heteroatom (C−O, C−N, C−S) bond‐forming reactions that are usually promoted by Ru, Ir, Pd, Ni, and Cu metal catalysts. In this trait, numerous methods were adopted to synthesize several pharmaceutically valuable N‐ and O‐containing heteroaromatics using 1,2,3‐benzotriazin‐4(3H)‐one as an electrophilic coupling partner. This review involves the recent achievements related to the metal/organo‐catalyzed thermal and visible‐light mediated denitrogenative approaches with 1,2,3‐benzotriazin‐4(3H)‐ones towards the synthesis of imperative N‐heteroaromatic compounds. In addition, metal and oxidant‐free ortho‐functionalization of benzotriazinones by using suitable nucleophilic partners have been discussed. In particular, the most novel methods employing Ni and Pd metal catalysts that have emerged are exhibited. Specific attention has been paid to offering the detailed mechanistic pathway to explain the role of metal catalysts and the mechanism in the absence of metal catalysts in the denitrogenative reactions under a thermal/visible light medium.

Exceptional stability of spinel Ni–MgAl2O4 catalyst with ordered mesoporous structure for dry reforming of methane

The dry reforming of methane reaction holds significant importance for the comprehensive utilization of CO2 and CH4, contributing to carbon neutrality. However, due to the high reaction temperatures, catalyst deactivation due to carbon deposition and sintering remains a challenge. In this study, a one-pot method was employed to improve the solvent evaporation self-assembly process for the preparation of Ni–MgAl2O4 catalysts. The impact of calcination temperature (600 °C, 800 °C, and 1000 °C) on the ordered mesoporous structure of the catalyst was investigated. Catalysts without an ordered mesoporous structure, such as Ni–MgAl2O4-1000, suffered deactivation due to carbon deposition caused by the large size of Ni grains, while Ni–MgAl2O4-600 deactivated due to sintering caused by the lack of confinement effect of the support on Ni. Conversely, Ni–MgAl2O4 catalysts with an ordered mesoporous structure exhibited confinement effects on Ni metal, resulting in excellent resistance to carbon deposition and sintering. Further investigation into the effect of different loading methods of Ni on methane dry reforming was conducted. A comparison was made between Ni–MgAl2O4 (800 °C) prepared by the one-pot method and Ni/MgAl2O4 (800 °C) prepared by the impregnation method. It was observed that Ni–MgAl2O4 catalysts, with Ni incorporated into the support, exhibited strong interaction between Ni and the support. During a 500-h long-term reaction, both CO2 and CH4 conversion rates remained at 90% for Ni–MgAl2O4 catalysts, with less carbon deposition and slower grain growth rate, demonstrating excellent reaction activity and stability. In contrast, the performance of Ni/MgAl2O4 catalysts gradually declined after 260 h. Ni–MgAl2O4 catalysts with ordered mesopores and strong interaction between Ni and the support displayed superior resistance to carbon deposition and sintering.

Designing a Phenalenyl-Based Dinuclear Ni(II) Complex: An Electrocatalyst with Two Single Ni Sites for the Oxygen Evolution Reaction (OER).

A new dinuclear Ni(II) complex 1, [Ni2II(dtbh-PLY)2], is synthesized from 9-(2-(3,6-di-tert-butyl-2-hydroxybenzylidene)hydrazineyl)-1H-phenalen-1-one, dtbh-PLYH2 ligand, and structurally characterized by various analytical tools including the single-crystal X-ray diffraction (SCXRD) technique. In the solid state, both Ni(II) metal centers in complex 1 exist in a distorted square planar geometry and display the presence of rare Ni···H-C anagostic interactions to form a one-dimensional (1-D) linear motif in the supramolecular array. Complex 1 is further stabilized in the solid state by π-π-stacking interactions between the highly delocalized phenalenyl rings. The redox features of complex 1 have been analyzed by the cyclic voltammetry (CV) technique in solution as well as in the solid state, revealing the crucial involvement of both the Ni(II) metal centers for undergoing quasi-reversible oxidation reactions on the application of an anodic sweep. A complex 1-modified glassy carbon electrode, GC-1, is employed as an electrocatalyst for oxygen evolution reaction (OER) in 1.0 M KOH, giving an OER onset at 1.45 V, and very low OER overpotential, 300 mV vs the reversible hydrogen electrode (RHE) to reach 10 mA cm-2 current density. Furthermore, GC-1 displayed fast OER kinetics with a Tafel slope of 40 mV dec-1, a significantly lower Tafel slope value than those of previously reported molecular Ni(II) catalysts. In situ electrochemical experiments and postoperational UV-vis, Fourier transform infrared (FT-IR), scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDS), and X-ray photoelectron spectroscopy (XPS) studies were performed to analyze the stability of the molecular nature of complex 1 and to gain reasonable insights into the true OER catalyst.

Surface exsolving perovskite ceramics as catalyst for microwave methane pyrolysis to co-generate hydrogen and carbon nanotube

In this study, we have successfully developed a novel surface exsolving perovskite ceramic, which demonstrates the ability to simultaneously generate COx-free hydrogen and carbon nanotubes (CNTs) through methane pyrolysis under the influence of microwave irradiation. We conducted an extensive survey and optimization of various perovskite materials specifically tailored for microwave applications. Among the materials investigated, nickel-doped strontium titanium oxide (STON) emerged as the most promising candidate, exhibiting both a satisfactory methane conversion rate and excellent responsiveness to microwave irradiation. Refinement of STON was carried out by fine-tuning the Ni content, optimizing the reduction dwell time, and adjusting the reduction temperature. Notably, SrTiNi0.08O3 (STON8), demonstrated an impressive initial methane conversion rate of up to 40%. Transmission Electron Microscopy (TEM) provided visual evidence of the correlation between Ni content and reduction temperature, with respect to the exsolved Ni metal particle size. This finding highlights the immense potential of surface exsolving perovskite ceramics as a highly effective catalyst for the simultaneous production of CNTs and COx-free hydrogen via methane pyrolysis under microwave irradiation. It represents a step forward in the field of catalytic materials and microwave-driven processes.

Potential availability of metals in anaerobic mono- and co-digestion of pig manure and maize

This study aims to analyse the potential availability of essential metals including as Co, Fe, Ni, Zn, Mn, and Cu and non-essential metals such as Pb, Cr, and Cd within anaerobic mono- and co-digestion of pig manure and maize. The metals partitioning was determined using the Modified BCR (European Community Bureau of Reference) sequential extraction at defined intervals over a 45-days period, correlating changes in metals speciation with key digestion variables. The findings revealed that Cr, Cu, Fe, and Pb were predominantly associated with the oxidisable fraction, while Zn, Mn, and Cd were potentially available in both processes. Notably, NH4+-N and the VFAs, except propionic acid, correlated significantly with the available fractions of Co, Mn, Ni, Zn, Cr, and Pb during mono-digestion of pig manure. The wider pH range and the chemical properties of the feedstock in co-digestion resulted in varied correlations between the metals availability and the digestion variables.

Graphite sheet-supported bimetallic RhNi thin film alloys for enhanced and durable hydrogen evolution in acidic environments

Noble metal-based materials are excellent catalysts for hydrogen production from water electrolysis, but their high cost and limited availability hinder widespread use. However, precious metals can be effectively utilized in catalysts by forming alloys with low-cost 3d transition metals, thereby reducing the need for precious metals, while enhancing the performance. In this study, aerosol-assisted chemical vapor deposition was employed to deposit bimetallic rhodium-nickel (RhNi) alloy thin films on a graphite sheet for hydrogen evolution reaction (HER) catalysis in a 0.5 M H2SO4 solution. Thin-film morphological patterns were significantly changed as the deposition time varied from 45 to 135 min. The RhNi alloy fabricated for 90 min outperformed its counterparts, displaying lower overpotential of 40 and 197 mV at 10 and 1000 mA cm−2, small Tafel kinetics (54 mV dec−1), high conductivity (0.57 Ω) and large electrochemical surface area (3312 cm2), and extended stability (48 h) compared to pure Rh metal and other reported catalysts. The superior HER performance arises from the synergistic effects between Rh and Ni metals, coupled with a uniform layer of spherical particles that enhance conductive properties and reaction rates by providing maximized active sites on graphite surface. This work provides valuable guidelines for efficiently preparing highly active and durable thin-film electrocatalyst within short time span and applying directly in fuel cell for hydrogen production.

Piroxicam analogue metal complexes: Synthesis, crystal structures, molecular modeling and biological studies

In recent decades, metal‐based drugs have gained considerable attention all over the world because of their enhanced therapeutic potential. The piroxicam analogue, that is, 2‐Benzyl‐4‐hydroxy‐1,1‐dioxo‐1,2‐dihydro‐1λ6‐benzo [e][1,2] thiazine‐3‐carboxylic acid pyridin‐2‐yl amide 1 was synthesized and coupled with Mn (II), Co (II), Ni (II), Cu (II) and Zn (II) metal ions to isolate complexes 2–6. The N,O‐bidentate chelator coordinated with the metal center via pyridyl nitrogen and amide oxygen atoms by forming six‐membered ring system. Several analytical techniques like UV–Vis, FT‐IR, 1H NMR, magnetic susceptibility, and elemental analysis were performed to confirm the syntheses of the octahedral complexes. The conductance measurement was employed to determine the non‐electrolytic nature of the complexes. The molecular structures of manganese (II) 2, cobalt (II) 3, and zinc (II) 6, complexes were confirmed by single beam X‐ray crystallography revealing the monoclinic crystal system with P21/c space group. The crystallographic data was utilized to carry out the DFT studies, which were found in line with the experimental data. The antioxidant (DPPH, FRAP) and antibacterial activities were performed to determine the therapeutic potential of these synthesized compounds. These studies indicated that understudied compounds have potential as therapeutic agents and they may be used as drug candidates in the future. The in‐silico studies also aligned with the in‐vitro potential of the targeted compounds.

Comparison of heavy metal residue in selected processed canned tomato paste and bottled tomato sauce using atomic absorption spectrometry

Heavy metals are used to manufacture various types of packaging materials such as cans and glass bottle containers. Determination of heavy metal concentration presence in processed food products is crucial to identify specific possibly hazard metal contaminants and create public awareness upon consumption. A total of ten samples consisting of five different brands of canned tomato paste and bottled tomato sauce sold in Malaysia were analysed for the concentration of lead (Pb), cadmium (Cd), iron (Fe), zinc (Zn), chromium (Cr) and nickel (Ni) metals residues by Atomic Absorption Spectrometry (AAS). The average heavy metals concentration of all samples was arranged in increasing order, Cd > Ni > Cr > Pb > Zn > Fe. The highest level of metal was Fe (69.93 mg/kg) while the lowest was Cd (0.01 mg/kg). The concentration of Pb, Cr and Ni in all samples exceed the permissible limit set by the World Health Organisation 2011, the European Commission 2006 and the Malaysia Food Act and Regulation 1985 except Zn. There is a significant difference between heavy metal concentrations in canned tomato paste and bottled tomato sauce (p˂0.05). Therefore, this study suggests efficient monitoring and inspection of both agricultural environment quality and industrial processing procedures.

A new circulation in glycolysis of polyethylene terephthalate using MOF-based catalysts for environmental sustainability of plastic

The relentless growth of plastic has emerged as a significant environmental and human health concern. Catalytic glycolysis of polyethylene terephthalate (PET) has proven to be an effective solution. This study investigated a series of M−BDC (M = Ni, Co, Cu, and Zn) metal–organic frameworks as catalysts for PET glycolysis. Zn−BDC exhibited the best experimental performance. Subsequently, the effects of operating conditions were optimized for the first time through a comprehensive investigation using a model based on deep neural networks (DNNs). The guidance of the DNN model resulted in a BHET selectivity as high as 0.95, outperforming most current heterogeneous catalysts for PET depolymerization. Furthermore, the apparent activation energy was also estimated by kinetic study. In addition, our designed system exhibits high durability after five consecutive runs, reflecting its promising escalation at the industrial level. Notably, the fabrication of the M−BDC framework can utilize the organic linker terephthalic acid (TPA) derived from the BHET monomer. By applying this strategy, we have achieved a significant advancement towards closed-loop PET recycling, contributing to a more comprehensive definition of sustainable development.

Performance of sulfided NiMo catalyst supported on pillared bentonite Al and Ti under hydrodeoxygenation reaction of guaiacol

Bio-crude oil is known to be sustainable, eco-environmentally, and an alternative energy source produced by biomass pyrolysis. However, its quality remains relatively low due to a higher oxygen concentration compared to liquid fuels from fossils. Therefore, an upgrading process is necessary through the catalytic hydrodeoxygenation (HDO) process. This work synthesized pillared bentonite using Al and Ti metals as the pillaring agent to produce Al-PILC and Ti-PILC as catalyst support for sulfided NiMo. Their catalytic activity in HDO reaction using guaiacol as a model compound of bio-crude oil were also evaluated. Characterization of the bentonite-pillared materials, including Al-PILC, Mo/Al-PILC, NiMo/Al-PILC, Ti-PILC, Mo/Ti-PILC, and NiMo/Ti-PILC, was performed using Surface Area Analyzer, X-ray Diffractometer (XRD), Temperature-Programmed Desorption of ammonia (NH3-TPD), X-Ray Fluorescence (XRF), and Scanning Electron Microscope (SEM) techniques. The characterization results confirm the pillarization process of bentonite using Al and Ti metals as the pillaring agent, and the preparation of the NiMo catalyst using the stepwise impregnation method was successfully prepared. The NiMo/Ti-PILC catalyst performs a superior conversion value on the HDO guaiacol reaction than other catalysts. A well dispersion of Mo and Ni metals on the surface support (NiMo/Ti-PILC), thus creating numerous active sites of the catalyst after the sulfidation. Variations in time and temperature during the HDO guaiacol reaction significantly affected the conversion.

Catalytic Cracking of Oily Sludge using Nickel Metal Catalyst Embedded in Silica Derived from Adsorbent in a Gas Process Plant

Abstract. One of the Oily Sludge (OS) recycling methods is through catalytic cracking. This process involves the reaction breaking down large molecules into smaller ones with the help of a catalyst. Nickel (Ni) metal is often used as a catalyst because it can increase fuel liquid yield while reducing the coke formation. To enhance its performance, Ni metal can be embedded in a carrier material like Silica to form the Ni-Silica catalyst. In this research, OS sourced from a Gas Process Plant is treated with catalytic cracking using Ni-Silica, where the Silica used is derived from an Adsorbent activated with NaOH. Optimization of the cracking conditions is carried out using Response Surface Methodology (RSM) with a Box-Behnken design. The optimized cracking reaction conditions include temperature (713 K, 723 K, and 733 K), time (50 min, 60 min, and 70 min), and catalyst-to-OS ratio of 1:5, 1:6, and 1:7. Statistical analysis indicates that the relationship between the reaction condition variables and the Oil Liquid Product (OLP) falls into the moderate category, as shown by the coefficient of determination (R²) of 0.5. The calculated F-value for the deviation from the mathematical model is smaller than the F-Table value (9.2) at both 5% and 1% significance levels, with a value of 0.6. This indicates that the mathematical model generated can be accepted as the mathematical model within the range of reaction conditions in this study. Calculus analysis reveals that the optimum reaction conditions are a temperature of 717.34 K, a time of 58.58 min, and a catalyst-to-OS ratio of 1:6, 15. Canonical analysis indicates that for OLP, λ1= [-12.38], λ2= [-2.27], and λ3= [4.50], where lambda values indicate that the most sensitive response surface parameter for OLP is temperature, followed by the catalyst-to-sample ratio, and the least sensitive is reaction time. Keywords: Catalytic Cracking, Ni Metal, OS, RSM, Silica

Optimization of TLPS Bonding Process and Joint Property using Ni-Sn Paste for High Temperature Power Module Applications

Recently, as interest in eco-friendly vehicles such as electric and hybrid vehicles increases, the demand for power semiconductors, a key component, is also increasing. Power semiconductors convert, distribute, and control power and operate in harsh environments such as high temperature and high pressure. In order to ensure stable reliability in such harsh environments, research on a technology that can stably form joints even at high temperatures is essential. Transitional liquid phase (TLP) bonding was proposed as a high-temperature power semiconductor chip bonding technology, which has the advantage of forming an intermetallic compound (IMC) phase with a high melting point at the joint. However, it takes a long time to convert the joint into full IMC phase. Therefore, in this study, in order to shorten the process time, a paste was manufactured by mixing high-melting point Ni metal powder and low-melting point Sn metal power, and a joint was formed through a TLPS (Transition liquid phase sintering) bonding using the paste. Pastes of different compositions were prepared by adjusting the ratio of Ni and Sn powders. The chip and substrate were bonded through a thermocompression (TC) bonding process, and the highest shear strength was obtained at a bonding temperature of 250 ℃ for 10 min. Heat treatment was performed at 200 ℃ for up to 500 h to evaluate the high temperature long-term reliability of the joints. The Ni-Sn TLPS bonded joints remained reliable joints after a long-term aging test at a high temperature of 200 ℃.

Unveiling the catalytic behaviour of LaNiO3 and La2NiO4 for dry reforming of methane

Comprehending the physicochemical characteristics of catalysts is essential for establishing the “structure-activity/property” correlations, making it crucial for catalyst advancement and the elucidation of reaction mechanisms. Here, we investigated combustion-synthesized perovskite LaNiO3 and layered perovskite La2NiO4, with mechanistic in situ FTIR studies for the first time in the context of sustainable syngas synthesis via dry reforming of methane. Time-on-stream experiments revealed that the as-synthesized LaNiO3 outperformed La2NiO4 initially, however, the used La2NiO4 exhibited improved catalytic activity with conversion of CH4 and CO2 to 63 and 82 %, respectively. Thermogravimetric analysis demonstrated insignificant coke formation over LaNiO3 with a rate of 1 × 10−3 mgc/gcat. h. Detailed compositional and species analysis unveiled the in-situ formation of metallic Ni0 during the reactions, which significantly influenced catalytic activity. H2-TPR studies indicated a higher reducibility of LaNiO3 with a total H2-uptake of 69.18 μ mol g−1 in contrast to 33.48 μ mol g−1 over La2NiO4. In situ FTIR and CO2-TPD studies revealed the higher basicity of LaNiO3 compared to La2NiO4, enhancing CO2 adsorption to a greater extent. This difference in reducibility, stemming from structural properties and availability of active basic sites, contributes to the distinct catalytic behaviours of both LaNiO3 and La2NiO4.

A general strategy for Ni0–NiOOH hybrid catalyst of high hydrogen evolution activity

Ni-based hybrid catalysts consisting of different components in variant valence state have the synergistic effect on boosting hydrogen evolution reaction (HER) activity. A general strategy is developed to achieve a Ni0–NiOOH HER hybrid catalyst, which needs to produce metal Ni0 and Ni(OH)2 concurrently. The strategy is demonstrated by two approaches, both of which include two electrochemical steps. To regular the content of the components in the hybrid catalyst, l-histidine and nitrate ions are introduced to the electrolyte in order to controlling the generation rate of Ni0 and Ni(OH)2. In terms of the two-step electrochemical technology, the pre-catalyst Ni0–Ni(OH)2 is electrochemically deposited firstly, and then electrochemical oxidized to Ni0–NiOOH, wherein Ni0 and NiOOH in different valence act as *H and *OH absorption sites, respectively. The XRD, TEM and XPS results demonstrate the coexistence of Ni0 and Ni(OH)2 in the pre-catalyst and the conversion of Ni(OH)2 to NiOOH in the final catalyst. Electrochemical tests show that the Ni0–NiOOH hybrid catalysts exhibit excellent HER activity. The overpotentials at 10 and 50 mA cm−2 are 39 mV and 88 mV, respectively, and the catalyst keeps a durable stability at 50 mA cm−2 for over 100 h. The present results suggest that the structure-performance correlations of the Ni0–NiOOH hybrid catalyst could be manipulated implementing this general deposition strategy.

Gasification Reaction on CeO2(111) and Effects on the Structural and Electronic Properties of Adsorption Molecules

AbstractProducing hydrogen (H2) from biomass gasification offers exceptional benefits regarding renewable energy sources, zero‐carbon emission, cost‐effective processes, and high efficiency. The addition of catalysts to biomass gasification could accelerate the process and minimize the formation of coke. However, the catalyst deactivation caused by carbon deposition, poisoning, and sintering is still a significant problem in the gasification process. Therefore, achieving sustainable exploitation of the renewable natural resource of biomass requires substantial development and optimization of the present gasification process. The efficiency of gasification might decrease because of such a process. In this study, CeO2(111) is chosen to investigate the analysis of adsorption molecules during catalytic gasification using the density functional theory method. Three catalyst models, CeO2(111), Zr‐CeO2(111), and Ni‐CeO2(111), have been studied in this work in terms of structural, electronic, and adsorption molecule properties. The structural and electronic properties of the modified catalyst model show the ligand and strain effect on the alloy, with the addition of Zr and Ni as second metals promoting the adsorption capability. Searching for active sites is also carried out by adsorption of selected atoms and molecules and used as a preliminary study to find possible active sites for gasification reactions. The Zr‐CeO2(111) and Ni‐CeO2 catalysts exhibit better adsorption ability on atomics and molecules. The Zr and Ni metals are suitable second metal candidates for the catalyst to proceed with the gasification reaction and simultaneously reduce carbon deposition, poisoning, and sintering problems.

Applications of Ni and Ag metallizations at the solder/Cu interfaces in advanced high-power automobile interconnects: An electromigration study

An advanced Pb-free solder interconnect, Cu line/Cu pillar/Ni/Sn1.8Ag/Ag/Cu lead frame/Sn3Ag0.5Cu/Au/Ni(P)/Cu trace, using the flip-chip quad flat no‑lead (FCQFN) packaging technology was designed for high-power automobile applications. An electromigration study revealing the Ni and Ag metallization effects on the interfacial reaction was investigated. Current stressing was conducted at a 2 A direct current at 160 °C until the defined 200 %-electrical-resistance-rise failure occurrence. Electromigration induced a two-stage electrical resistance increase mode in the advanced automobile test vehicle with a mechanism transition time of 585 h, as evidenced by the in situ resistance monitoring. Phase transformation from the constituent phases into the predominant (Cu,Ni)6Sn5 and Cu3Sn intermetallic compounds (IMCs) at the interfaces was proposed to explain the rapid resistance rise in the early-stage electromigration. Void formation and coalescence due to the Kirkendall effect and volume shrinkage during the phase transformation were proposed to explain the following steady resistance increase after the critical current stressing time. Furthermore, the phase transformation and growth of the IMCs behaved divergently at different interfaces and electron flow directions. The rapid phase transformation occurred in the downstream Sn1.8Ag solder interconnect due to the accelerated Ni metallization dissolution and formed a complete IMC joint. The anisotropic diffusion driven by the competitive or synergetic effect between the electron wind force and chemical potential gradient was proposed to explain the asymmetric microstructures after the electromigration experiment. The application of Ag metallization benefited the flip-chip soldering process, and the layer-type Ag3Sn IMC served as a diffusion barrier against Sn/Cu interdiffusion at the solder/Cu lead frame interface during the solid-state electromigration. In contrast, the Ni metallization was designed as a diffusion barrier to hinder interdiffusion and the undesirable Cu3Sn growth at the solder/Cu interface. The findings presented in this study could benefit the solder interconnect design with an appropriate metallization combination against undesirable electromigration failure.

Highly efficient enhancement of mechanical and tribological properties of Cu-based composites by addition of graphene-loaded Ni metal particles

The tight interface between graphene and Cu is the key to give full play to the comprehensive properties of Cu/C composites. In this study, reduced graphene oxide(RGO) was used as a reinforcing phase of Cu marix, and the interfacial bonding strength between RGO and Cu was enhanced by introducing Ni metal nanoparticles. RGO supported Ni nanosheets (Ni-RGO) were successfully prepared by in-situ chemical reduction of graphene oxide (GO) and the introduction of Ni nanoparticles into GO. Ni nanoparticles were tightly attached to the graphene sheets. The mechanical properties and tribological properties of Ni-RGO/Cu composites were significantly improved. The bending strength of Ni-RGO/Cu composites reached 162.2 MPa, which was much higher than that of the pure Cu. At the same time, Ni-RGO composites have the lowest wear rate, and the friction coefficient is stable between 0.1 and 0.2. The comprehensive performance of Ni-RGO composites is significantly enhanced due to the unique structure of Ni-RGO, and the introduction of Ni nanoparticles realizes the effective bonding between GO-Ni-Cu. This study provides a new and effective strategy for enhancing the interfacial bonding of Cu/C composites.