Fe-Ni Alloys Research Articles

Stress relief annealing of super Invar alloy: microstructure, soft magnetic and thermal expansion properties

Invar (Fe64Ni36) alloy is regarded as a prospective contender for thermal structural materials and transformers utilized in aerospace vehicles, in addition to electrical, and other applications, largely due to its markedly low expansion properties. It is noteworthy that the optimization of permeability and coercivity in Invar alloys has the potential to meet the requirements of a broader range of applications. Consequently, enhancing the soft magnetic properties and extending the low expansion intervals is crucial. The effects of stress relief annealing on the microstructure, soft magnetic properties, and thermal expansion behavior of super Invar alloy (Fe64Ni32Co4) are investigated. The findings indicate that the incorporation of Co has no impact on the phase structure of the Fe-Ni alloy, yet elevates the Curie temperature of the Fe-Ni alloy to 324.84°C. As the annealing temperature is increased, the grain diameter of the alloy increases gradually. Concurrently, the enhancement of density and magnetocrystalline isotropy diminishes the prevalence of lattice defects, which markedly influences the soft magnetic characteristics of super Invar alloy. At an annealing temperature of 1150°C, the material exhibits a saturation magnetic flux density of 1494 mT, a maximum permeability of 31.04mH/m, a coercivity of 13.52A/m, and a wide low expansion interval. This phenomenon can be attributed to random orientation, residual stress relief, and higher Curie temperatures. The results provide a comprehensive insight into the evolution of soft magnetic properties and their underlying mechanisms, covering a larger range of low expansion intervals.

Hydrogen-rich gas generation from enhanced catalytic cracking of biomass tar and related model compounds on Ni-Fe/ASA@HZSM-5 catalyst: Pathways and mechanisms

This study focused on the design of complex tar model compounds (CTMC) and synthesized a highly efficient aluminum dross (ASA) combined with HZSM-5 molecular sieve co-loaded bimetallic Ni-Fe catalyst (Ni-Fe/ASA@HZSM-5), comprehensively evaluated the catalytic cracking of real tar and its model compound by adjusting the injection amount and injection state of tar, and catalyst types to obtain hydrogen-rich gas with high H2 and low CO2 content. The results showed under the conditions of the injection amount of 0.6 mL/min, pyrolysis temperature of 600 °C, reforming temperature of 800 °C in the liquid phase, Ni-Fe/ASA@HZSM-5 displays excellent catalytic cracking performance with CTMC conversion efficiency of 87.80 % (79.46 % of gas yield and 34.20 vol% of H2 yield). The possible cracking paths between different components of CTMC in the Ni-Fe catalytic system were summarized by the experimental data and product distribution, the catalytic mechanism of Ni–Fe based catalysts can be attributed to the formation of a Ni-Fe alloy and the synergistic effect of ASA and HZSM-5 co-carrier. Further, the catalytic cracking pathway of CTMC was enhanced in the gas phase, the higher CTMC conversion efficiency of 93.68 %, gas yield (a mass fraction of 82.51 %) and H2 (a volume fraction of 33.59 %) were obtained from catalytic cracking of CTMC, the liquid yield decreased by 12.39 %, significantly improved the cracking degree and gas production capacity of CTMC. The real tar showed the same catalytic pyrolysis path and product distribution. Under the same cracking conditions, the yields of gas, liquid and char were 84.85 %, 12.00 % and 3.15 % respectively, and obtained the hydrogen yield of 55.29 mL/g. The CTMC simplifies the cracking process and reduces polymerization, provides insights into the cracking mechanisms of heavy components in biomass tar. Furthermore, the synergy of Ni and Fe contributed to greater activity for CTMC and real tar cracking, ASA combined with HZSM-5 molecular sieve co-loaded bimetallic Ni-Fe catalysts have a promising application potential as highly efficient catalysts for tar removal and reutilization.

Fe-promoted Ni nanocatalysts for hydrogenolysis of Klason lignin to monophenols

The efficient cleavage of lignin's inter-unit bonds is essential for its conversion into valuable monophenols. However, conventional Ni-based catalysts often suffer from poor metal dispersion, sintering, and limited catalytic activity. In this study, a series of bimetallic Ni2M/Al2O3 (M=Fe/In/Mn/Cu/Co) catalysts were synthesized using layered double hydroxides as precursors. Among the metal promoters tested, Fe showed the highest efficacy in improving catalytic performance. NixFey/Al2O3 catalysts with varying Ni/Fe molar ratios exhibited superior activity due to the formation of Ni-Fe alloys and defect-rich FeOx species. The optimized Ni1.5Fe1.5/Al2O3 catalyst, characterized by well-dispersed small metal particles, strong Ni-Fe interactions, abundant surface oxygen vacancies, and a high density of strong acid sites, achieved a monophenol yield of 16.6 wt% from the hydrogenolysis of Klason lignin under mild reaction conditions (240°C, 4 hours, 1 MPa initial H2). This work presents a novel approach for developing highly active bimetallic catalysts for lignin depolymerization, offering insights into the design of efficient catalysts for lignin valorization.

In-situ confinement growth of FeNi alloy within B/N co-doped carbon nanotubes as efficient electrocatalyst for water splitting

Developing low-cost and efficient catalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) still remains a challenge in water electrolysis. Herein, FeNi alloy encapsulated within boron and nitrogen co-doped carbon (FeNi@BNC) nanotubes are synthesized through a simple one-step pyrolysis method using FeCl3·6H2O, NiCl2·6H2O, H3BO3, urea and PEG-2000 as precursors. The BNC nanotubes are quite requisite for dispersing and stabilizing FeNi alloy nanoparticles (NPs) during pyrolysis. Benefiting from the synergistic catalytic effect of Fe and Ni, as well as the confinement effect of BNC nanotubes, such FeNi@BNC catalyst demonstrates impressive activities for both HER and OER, much superior to pristine Fe@BNC and Ni@BNC. Notably, the overpotentials needed to achieve a current density of 10 mA·cm−2 are just 230 mV for HER and 280 mV for OER. Moreover, the FeNi@BNC catalyst demonstrates significant stability, showing no noticeable degradation during potentiostatic electrolysis or repeated CV tests. Furthermore, FeNi@BNC exhibits remarkable activity for overall water splitting, requiring cell voltages of just 1.24 V and 1.60 V vs. RHE to achieve current densities of 10 mA·cm−2 and 20 mA·cm−2, respectively. This study introduces a novel strategy for developing bifunctional electrocatalysts with high-efficiency water splitting performance.

Elucidating the efficacious capacitive deionization defluorination behaviors of heteroatom-doped hierarchical porous carbon nanofibers membrane

Heteroatom-doped porous carbons, particularly those incorporating nitrogen functionalities, demonstrate exceptional electrochemical properties advantageous for capacitive deionization (CDI) defluorination. Nevertheless, the underlying mechanism of fluoride removal remains inadequately understood, warranting comprehensive investigation to facilitate the practical implementation of CDI technology. Herein, a novel nitrogen-doped hierarchical porous carbon nanofiber membrane (HPCNM) derived from a hydrochloric acid etched FeNi3@CNFs (FeNi3 alloy encapsulated within carbon nanofibers) network was reasonably designed and synthesized for CDI defluorination. The HPCNM electrode exhibited superior defluorination capabilities, attributed to its distinctive hierarchical porosity and compositional architecture. The novel material achieves remarkable performance metrics, including a defluorination capacity of 58.38 mg g−1, rapid ion removal kinetics (0.97 mg g−1 min−1), and maintained efficiency throughout 20 operational cycles. Density functional theory (DFT) calculations indicate that nitrogen-doped carbon (NC) preferentially adsorbs fluoride, exhibiting the lowest adsorption energy. Fluoride interacts with NC through a combination of weak covalent bonds and van der Waals forces. Its inherent electronegativity, hardness, and high electrophilicity index, contrasted with low softness and nucleophilicity, facilitate the selective adsorption. Furthermore, an optimized NC electrode, operating at 1.2 V in simulated industrial wastewater, achieved fluoride removal compliant with national standards, demonstrating its practical applicability for treating contaminated effluent. These findings advance the understanding of selective fluoride removal, contributing to the development of targeted electrodes for industrial applications.

The effects of Cobalt doping on the structural, electronic, magnetic, and thermodynamic characteristics of the L10-FeNi alloy: First-principle calculations

This study conducts a computational analysis employing density functional theory (DFT) to investigate the effects of Cobalt doping as substitutional defects on the structural, electronic, magnetic, and thermodynamic characteristics of the L 10− FeNi alloy. The aim of this study was to explore their potential applications as alternatives to rare-earth permanent magnets. Two types of substitutional Co-doping (ONi/OFe) in the Ni/Fe-site of the parent alloy have been investigated. The computed formation energy indicates that the incorporation of cobalt defects increases the structural stability of tetragonally distorted L10FeNi via Co-doping. The results we obtained demonstrate that the FeNi:Co (ONi) in the L10-structure has a large enhancement in magnetic moments and saturation magnetization (Ms), whereas for the FeNi:Co (OFe), has a small reduction in Ms. Furthermore, reducing the concentration of cobalt in L10 FeNi:Co alloys is advantageous in diminishing the volumetric thermal expansion coefficient, consequently lowering the Debye temperature and weakening atom interactions. Therefore, Co-substituted FeNi alloys hold promise as potential candidates for rare-earth-free permanent magnets.

An in-situ high-throughput study of the Invar effect in the Fe–Ni–Co system

The Fe–Ni based classical Invar alloy and the Fe–Ni–Co based super Invar alloy are the basis for designing multicomponent alloys with low thermal expansion. In this work, we applied in-situ high-throughput experimental methods to map chemical composition, crystal structure, coefficient of thermal expansion (CTE) and magnetism in the Fe–Ni–Co system. The distribution of CTE (80–200℃) measured by the in-situ micro-beam X-ray diffraction on the combinatorial materials chips (CMC) showed low CTE regions in agreement with previous reports. Combined with the MOKE measurements, the μ̅−e̅ relation of the Fe–Ni–Co ternary FCC phase is found to follow the reported FCC Fe–Ni alloys in the Slater-Pauling curve. A low CTE region is centred at e̅ = 26.7 and μ̅= 1.26 μB in the Slater-Pauling curve. The observed low CTE zone not only matches with the classical Invar and super Invar alloys but also agrees with the reported Fe–Ni–Co based multicomponent alloys with a small amount of doping (< 5 at%) by Cu, Cr, Mn etc. The effect of Cr addition (> 5 at%) to Fe–Ni–Co alloys on the Invar effect is further discussed in terms of the interplay between magnetism and austinite stability.

Self-supported bifunctional porous Ni–Fe-based electrode via one-step reduction method for efficient water splitting

Efficient, inexpensive, and robust bifunctional electrodes are crucial for water splitting. Herein, the three-dimensional hierarchical porous nickel-iron (Ni–Fe)- based monolith is directly fabricated through a one-step reduction approach of their oxide precursors under a hydrogen atmosphere. The Ni–Fe alloy as the active material of water splitting is simultaneously formed during the reduction process and water is the only by-product, which is facile and environmentally friendly. The effects of the reduction temperatures and the Fe contents on the microstructures and composition of the obtained Ni–Fe samples are systematically investigated. The optimized Ni–Fe-based monolith is used as a self-supporting electrode for oxygen evolution reaction, its electro-oxidized derivatives show a low overpotential of 217 mV at 10 mA cm−2 and an ultralow Tafel slope of 31 mV dec−1 in 1 M KOH. Furthermore, the electrolyzer consisting of the bifunctional electrode demonstrates outstanding performance of 1.49 V at 10 mA cm−2 and exceptional long-term stability over 1000 h at 50 mA cm−2, surpassing the majority of alkaline electrolyzers utilizing Ni–Fe-based electrodes.

Sound velocities and thermal equation of state of fcc-iron-nickel alloys at high pressure and high temperature: Implications for the cores of Moon and several planets

Fcc-Fe-Ni alloy is believed to be the most dominant solid constitute of moderate-sized terrestrial planetary cores. Investigating the physical properties, especially the density and sound velocity of Fe-Ni alloys and comparing them with seismic observations is an indispensable approach to constructing compositional models for planetary interiors. In this study, we conducted sound velocity measurements on Fe-Ni alloys with 10 wt.% and 20 wt.% Ni up to ∼13.5 GPa and 1073 K, using the ultrasonic interferometry technique in a multi-anvil apparatus in conjunction with synchrotron radiation. By fitting the experimental data to finite strain equations, the bulk and shear moduli and their pressure and temperature derivatives are derived, yielding KS0 =145.8(14) GPa, G0 = 73.2(7) GPa, KS0’ = 5.89(24), G0’ = 2.89(8), (∂KS/∂T)P = -0.0181(12) GPa/K and (∂G/∂T)P = -0.0393(10) GPa/K for fcc-Fe80Ni20. An examination of the density-velocity relationship shows that compressional wave velocity is insensitive to temperature within the current pressure and temperature range, while shear wave velocity exhibits a large reduction with increasing temperature. Extrapolation of the sound velocities following the finite strain theories suggests that much slower Vs should be expected at pressure and temperature conditions corresponding to those of the lunar core. Possible core density and velocity profiles for other moderate planets and satellites, such as Mars, Mercury, and Ganymede are also calculated.

Production of Ni[sbnd]Fe alloy by combined recycling of waste nickel-metal hydride batteries and waste toner powder

This paper elucidates a novel and sustainable way of bringing two major sub e-waste streams (waste electrodes of Ni-MH battery and waste toner powder) together to manufacture NiFe alloy. Reduction of oxides (present in the Ni-MH battery electrode) with carbon sourced from waste toner was performed at 1550 °C which observed the formation of NiFe alloy as reaction proceeded to 1 h. Percentages of waste toner in the 2 g feed material containing waste electrode mass was varied to study the metal/slag formation and separation alike. The product and slag phases were both analysed by X-ray powder diffraction, Scanning electron microscopy, Energy dispersive x-ray spectroscopy, Laser induced breakdown spectrometer to confirm the formation and metallic composition of the NiFe alloy (>75 % Ni and > 14 % Fe) and the mixture of rare earth oxides present in the slag phase. In addition to manufacturing the metallic alloy, which evinces a possibility of being used as a feedstock in industrial applications, this innovative recycling technique also brings down the burden on landfills.

An Angstrom-Scale Protective Skin Grown In Situ on Perovskite Oxide to Enhance Stability in Water.

The utilization of perovskite oxide as a catalyst for aqueous reactions is promising but challenging in stability. Here, we propose an in situ growth strategy that constructs an ultrathin protective skin on the Sr0.9Fe0.81Ta0.09Ni0.1O3-δ perovskite surface and thus effectively solves the stability issue. Using a spherical aberration-corrected transmission electron microscope, we observe the coexistence of an angstrom-scale (~7 Å) Fe2O3 protective skin and FeNi alloy nanoparticles. A number of alloy nanoparticles grow along with the skin and uniformly take root on the skin surface. Such a hierarchical structure can reconstruct the surface electronic structure and suppress the ion leaching of perovskite oxide in water. Benefiting from this unique structure, the catalyst has experienced a substantial increase (800 h, more than three orders of magnitude) in its stable operation time in water (for example, in a hydrogen evolution reaction). These results provide valuable insight into solid-solid phase transitions and have substantial implications for using structural defects at surfaces to modulate mass transport and transformation kinetics. Our strategy is sufficiently simple and can be used to subtly manipulate the catalyst structures to improve the performance of perovskite-based catalysts and potentially other oxide catalysts for a wide range of reactions.

An Angstrom‐Scale Protective Skin Grown In Situ on Perovskite Oxide to Enhance Stability in Water

AbstractThe utilization of perovskite oxide as a catalyst for aqueous reactions is promising but challenging in stability. Here, we propose an in situ growth strategy that constructs an ultrathin protective skin on the Sr0.9Fe0.81Ta0.09Ni0.1O3‐δ perovskite surface and thus effectively solves the stability issue. Using a spherical aberration‐corrected transmission electron microscope, we observe the coexistence of an angstrom‐scale (~7 Å) Fe2O3 protective skin and FeNi alloy nanoparticles. A number of alloy nanoparticles grow along with the skin and uniformly take root on the skin surface. Such a hierarchical structure can reconstruct the surface electronic structure and suppress the ion leaching of perovskite oxide in water. Benefiting from this unique structure, the catalyst has experienced a substantial increase (800 h, more than three orders of magnitude) in its stable operation time in water (for example, in a hydrogen evolution reaction). These results provide valuable insight into solid‐solid phase transitions and have substantial implications for using structural defects at surfaces to modulate mass transport and transformation kinetics. Our strategy is sufficiently simple and can be used to subtly manipulate the catalyst structures to improve the performance of perovskite‐based catalysts and potentially other oxide catalysts for a wide range of reactions.

Iron and nickel based alloy nanoparticles anchored on phosphorus-modified carbon-nitrogen plane enhances electrochemical nitrate reduction to ammonia

The catalysts of iron and nickel nanoparticles anchored on carbon–nitrogen plane (FeNi-CN) are considered as the potential candidates for promising electrochemical nitrate reduction to ammonia (ENO3RR). However, the high d-orbital energy levels of iron and nickel sites coordinated with nitrogen atoms often lead to overly strong adsorption of reaction intermediates on active sites, severely limiting the improvement of catalytic performance. Herein, a catalyst FeNi3@P-NC consisting FeNi3 alloy nanoparticles confined in phosphorus (P)-modified carbon–nitrogen plane is successfully fabricated, where the electron withdrawal effect induced by P on the carbon–nitrogen plane decreases the d-orbital energy, and optimizes the d-band center of FeNi alloy, thus weakening the overly strong adsorption of intermediates at the metal-N sites and thereby improving NO3RR activity. The prepared FeNi3@P-NC catalyst exhibits exceptional NO3RR performance with a 93 ± 4.5 % Faradaic efficiency of NH3 production (FENH3) and a high NH3 yield rate (YNH3) of 9633 ± 227.3 μg h−1 cm−2 at −0.7 V versus Reversible Hydrogen Electrode (vs. RHE) under alkaline medium. Importantly, FeNi3@P-NC also demonstrates superior catalytic stability and durability, which maintains stability over twenty-five successive electrochemical cycles and for 50 h of continuous electrolysis at 100 mA cm−2.

Breaking the limitations of activity and stability in powdered materials for oxygen evolution reaction: The critical role of catalyst-inducing seeds

Powdered catalysts are extensively employed in industrial-scale energy conversion devices but struggle with weak powder-substrate adhesion and inherent instability in gas-evolving and highly oxidative oxygen evolution reactions (OER). This work introduces an innovative strategy in which powdered materials serve a critical role as catalyst-inducing seeds to break these limitations. Specifically, powdered Ti2CTx MXene with anchored cobalt single atoms (Co-SAs) shows negligible catalytic activity on its own but serves as catalyst-inducing seeds, significantly enhancing the catalytic activity of the conductive FeNi substrate. Mechanistic studies demonstrate that Co-SAs accelerate the oxidation rate of Ti2CTx, leading to the micro-battery corrosion behavior between oxidized Co/Ti2CTx and FeNi alloy, which generates highly OER-active corrosion products tightly bonded to FeNi alloy, thereby enhancing catalytic activity and ensuring stability. The prepared porous electrode shows a low overpotential of 303 mV to deliver an ultra-high current density of 1000 mA cm−2 and maintains activity for 1200 hours under high current density conditions, rivaling advanced self-supporting electrodes. Moreover, replacing Co in Co/Ti2CTx with metals like Fe, Ni or Mn, yields comparable effects, suggesting the scalability of catalyst-inducing seeds. This approach breaks traditional limitations of powdered materials in OER, offering an effective pathway to engineer advanced catalytic electrodes.

A new nanoindentation approach for determining both indentation size effect and continuous apparent activation volume during loading of nanocrystalline Ni and Ni-20 wt.% Fe alloy

A new nanoindentation approach is developed in this study to determine both indentation size effect (ISE) and continuous apparent activation volume () during loading of nanocrystalline nickel (NC Ni) and nanocrystalline nickel-20 wt.% iron alloy (NC Ni-Fe alloy). This approach involves conducting nanoindentation tests under loading modes controlled by both constant strain rate (CSR) and constant loading rate (CLR). Firstly, a new empirical expression for the parameter in the modified Nix-Gao model is established to study the strain rate dependence of the ISEs created in the CSR and CLR tests. Then, continuous data of each individual sample (indentation) during loading are obtained in the CLR test through the alternative use of continuous stiffness measurement technique. The stress dependence of is analyzed based on Duhamel et al.’s model, which considers the role of vacancies generated during inhomogeneous dislocation nucleation. Finally, based on the above experimental and theoretical work as well as transmission electron microscopy observation, the influences of loading mode, loading rate, and material properties (stacking fault energy) on resulting intrinsic hardness of NC Ni and NC Ni-Fe alloy are analyzed. The nanoindentation approach developed in this study provides profound insights into the mechanical behaviors during loading and underlying mechanisms of materials.

Decrypting Synergy of Alloy & Metal Nanoparticles Within Nitrogen-Doped Carbon Nanosheets for Zn-Air Batteries with Ultralong Cycling Stability.

The exploration of efficient, robust, and low-cost bifunctional electrocatalysts to drive the commercial application of Zn-air batteries (ZABs) is of great significance but still remains a challenge. Herein, a 1D coordination polymer (1D-CP) derived FeNi alloy & Co nanoparticles (NPs) co-implanted N-doped carbon nanosheets (FNC/NCS) is judiciously crafted and employed as a high-performance electrocatalyst for ultralong lifetime ZABs. The key to this strategy is the leveraging of metal-coordinated melamine to direct the pyrolysis of 1D-CP, enabling the in situ formation of well-dispersed FeNi alloy and Co NPs within the carbon matrix. The resulting FNC/NCS exhibits prominent oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) activity with a small overall oxygen potential difference (ΔE = 0.68V). Density functional theory (DFT) simulation demonstrates that the synergistic effect between FeNi alloy and Co NPs can reduce energy barriers, promote electron transfer, and optimize the formation of crucial intermediates, thereby largely boost ORR/OER activity of FNC/NCS. The FNC/NCS-assembled ZABs possess high specific capacity, large power density, and ultralong cycling life in both aqueous (> 3300h) and solid-state (150h) electrolytes. This work provides a viable strategy for 1D-CP-derived bifunctional electrocatalysts and dissects the synergistic effect between different metal species, affording significant guidance for the development of renewable energy materials.

Self-Adaptive Layering Structure of Nanoconfined Fe-Ni Liquids: Origin of the Liquid-Liquid Phase Transition.

Metallic liquids under confinement exhibit different properties compared to those of their corresponding bulk phases, such as miscibility, diffusion, and phase transitions. Unfortunately, the challenges in experimentally characterizing Fe-Ni liquids at the nanoscale and the high cost of first-principles simulations hindered the atom-level understanding that is necessary for controlling Fe-Ni liquids. Here, we report a comprehensive molecular dynamics study of the liquid Fe-Ni alloy confined within nanoslits. Driven by the slit size, the confined Fe-Ni liquid experiences the liquid-liquid phase transition (LLPT) that is characterized by layering transitions. Interestingly, during the LLPT, a transition liquid phase appears, separating two layering phases, which is accompanied by abnormal variations in density, potential energy, and pressure perpendicular to the wall. The Voronoi cluster analysis reveals a self-adaptive local structural evolution in confined Fe-Ni liquids during the LLPT. The effect of temperature, pressure, and composition on the LLPT is investigated. Based on the pressure-confinement phase diagram, the LLPT is mainly induced by confinement under high pressure, while under low pressure, the LLPT is mainly pressure-driven. Our research will stimulate more interest in the phase transition under confinement in a metallic system.

On the Strengthening Mechanism in Lath Martensite of As-Quenched Fe–Ni Alloys

On the Strengthening Mechanism in Lath Martensite of As-Quenched Fe–Ni Alloys

CeO2-confined Ni-Fe alloy enhanced high-temperature CO2 hydrogenation to CO

NiFe2O4 exhibits excellent redox properties and is widely applied in catalytic reactions. However, rapid inactivation under reaction conditions limited its industrial applications. In this study, CeO2-NiFe2O4 composite catalysts were synthesized, and the Reverse Water Gas Shift (RWGS) reaction was measured to reveal its CO2 hydrogenation performance under a high-temperature condition. NiFe2O4 catalysts got deactivated after being reduced to Fe-Ni alloy at 700 °C, decreasing the CO2 conversion rate. CeO2 addition can significantly improve its high-temperature activity, and 20CeO2-NiFe2O4 exhibited the best catalytic activity (80.85 %, 700 °C). The CeO2-confined maintained Ni-Fe alloy with a relatively small crystal size and larger specific surface area, supporting more active sites for CO2 hydrogenation. CeO2 addition induced higher oxygen vacancy concentration, enhancing CO2 activation and formates species formed on 20CeO2-NiFe2O4, resulting in higher CO2 conversion activity. In addition, 20CeO2-NiFe2O4 maintained its catalytic stability for 50 h at 700 °C. The CeO2 confined enhanced the high-temperature stability of Fe-Ni alloy. CeO2 and formed CeFeO3 dispersed in 20CeO2-NiFe2O4 inhibited excessive aggregation of Fe-Ni alloy, and CeO2 inhibited carbon deposition on Fe-Ni alloy, improving Fe-Ni alloy’s reaction stability under RWGS reaction conditions. CeO2 confined may give insight into improving metal stability under high-temperature and reductive conditions in heterogeneous catalysis.

Exploring multimetal interactions between FeNi3 alloy and Lu3Ga5O12 metal oxide for improved water splitting performance

The production of energy from fossil fuels generates greenhouse gases, leading to global warming and various environmental impacts. Extensive research into sustainable alternative fuels has identified hydrogen (H2) as a viable option. With net zero carbon emissions, hydrogen presents a promising solution for sustainable and renewable energy. This study employs a simple gel-matrix method to fabricate Ni-Fe alloy-based nanocomposites in alkaline media (1 M KOH). Achieving outstanding performance in hydrogen generation through the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), with impressive turn-over frequencies (TOF) of 2.98 s−1 at 177 mV and 1.48 s−1 at 219 mV. Nanocomposite’s unique structure enhances electroactive surface area (347.5 cm2/gram), extending electrocatalytic active sites and durability to 60 h. It shows excellent performance, characterized by low Tafel slopes of 50 mV/dec and 37 mV/dec, and minimal overpotentials of 219 mV for the oxygen evolution reaction (OER) and 177 mV for the hydrogen evolution reaction (HER), reaching a current density of 10 mA cm−2. This study presents a method for synthesizing high-performance, sustainable metal-alloy/garnet hybrid electrocatalysts, offering a new frontier in design of next-generation materials for advanced energy conversion technologies.