Fe-Ni Alloys Research Articles

Effect of Sodium Lauryl Sulfate on the Properties of the Electrodeposited Invar Alloy

In the OLED display manufacturing process, a fine metal mask (FMM) is used for the RGB side-by-side in precise positions. An Invar alloy with exceptionally low thermal expansion was used as the FMM material to prevent the deformation of the FMM by heat during the deposition process. The thickness of the FMM must be reduced to less than 10 microns to manufacture high-resolution OLED displays, making it essential to apply a bottom-up electrodeposition process. Moreover, controlling the interfacial energy of the cathode substrate and the electrolyte is necessary to achieve ion electrodeposition and peeling of the ultra-thin Fe-Ni plated on the cathode substrate during electrodeposition. Therefore, this study investigated the effect on the properties of the electrodeposited Fe-Ni alloy by controlling the amount of SLS content, which acts as a surfactant. The amount of SLS content was maintained in the range of 0 to 1 g/L, and the composition homogeneity, microstructure, and surface defects of the electrodeposited Fe-Ni alloy were investigated. Under low pH conditions, the composition was insignificantly changed depending on the difference in the amount of SLS content, and a uniform composition was observed. The findings of this research offer valuable insights for optimizing the electrodeposition process, which is crucial for producing high-resolution OLED displays with ultra-thin FMM, advancing display technology.

Bottom-up self-assembly strategy to construct ternary MoxC/Ni3Fe@GL as efficient water splitting electrocatalyst

Efficient and robust bifunctional non-precious metal electrocatalysts, used for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), are crucial to develop water splitting commercial applications. Herein, a bottom-up self-assembly strategy is proposed to construct ternary electrocatalysts of nitrogen-doped graphene-like carbon layers encapsulated MoxC (x = 1, 2) and Ni3Fe alloy nanoparticles (MoxC/Ni3Fe@GL) for efficient water electrolysis. The optimized sample (0.27MoxC/Ni1.5Fe@GL, 0.27 represent the mass of ammonium molybdate in the precursor) requires overpotentials (η10) of 88 and 150, 265 mV in 0.5 M H2SO4 for HER and 1.0 M KOH for HER and OER, respectively. Furthermore, as a bifunctional electrocatalyst in a two-electrode cell, 0.27MoxC/Ni1.5Fe@GL requires only 1.523 V at 10 mA cm−2, which surpasses the noble metal RuO2(+)||Pt/C(−) in 1.0 M KOH electrolyte, and shows excellent stability by working at 20 mA cm−2 long as 150 h. The superior electrocatalytic performance can mainly originate from MoxC and Ni3Fe alloys synergistically effected results. The partial doping of Ni or Fe atoms into Mo2C optimizes the electronic structure, making the intrinsic activity enhanced. On the other hand, the incorporation of MoxC heterophases effectively inhibits the Ni3Fe nanoparticles agglomeration, benefitting to expose more active sites. Moreover, the protection of encapsulated thin N-doped graphene-like carbon layers for the nanoparticles against corrosion, guarantees the long-time durability. This work provides a potential general bottom-up self-assembly approach to construct high-performance electrocatalysts with multiphase heterostructures with enriched abundant active sites and enhanced intrinsic activity for energy coversion fields.

Multi-metal catalysts for selective furfural hydrogenation: Toward biomass valorisation

The research presented here focuses on the design of non-noble transition metal-based bimetallic catalysts, prepared via a green sol-gel process (the urea-glass route), which leads to well-defined (in composition and size) and crystalline nanoparticles, with high surface area. The potential of these tailor-made catalysts for biomass-related model reactions is also presented. In particular, carbon supported Ni, Ni3Fe, Ni0.5Fe0.5, Ni0.5Fe0.5/Fe3C and Ni0.35Fe0.65/NiFe2O4 nanoparticles were synthesized and tested as-prepared, with no need for post-synthesis purification, activation, or co-catalysts addition. Results showed that these catalysts are active in the liquid-phase hydrogenation of furfural (FUR), with almost full conversion with Ni° catalyst, at 170 °C after 22 h, under 4 MPa hydrogen pressure, obtaining the highest yield towards tetrahydrofurfuryl alcohol (THFA) of 85%. More interesting, the incorporation of Fe, to form NiFe alloys, modifies the hydrogenating capacity of the catalyst, provoking a change in the selectivity pattern, from tetrahydrofurfuryl alcohol (THFA), obtained as the only product with Ni° nanoparticles, to furfuryl alcohol (FFA). Thus, high FFA and THFA yields can be obtained by modifying the nature of the metallic phase of samples synthesized with the urea-glass route, demonstrating the potential of this methodology for the preparation of active and selective catalysts for liquid-phase FUR hydrogenation.

Promoted degradation of tetracycline by FeNi alloys embedding in biochar activating peroxydisulfate: Performance and mechanism

Bimetallic FeNi alloys embedding into biochar (FeNi-BC) catalysts with different Fe/Ni molar ratio were fabricated using rose petal as biomaterials. The as-fabricated FeNi-BC was employed to activate peroxydisulfate (PDS) toward tetracycline (TC) degradation. The effects of Fe/Ni atomic ratio on the structure feature of FeNi-BC and PDS activation efficiency were explored in detail. Results show that the optimum Fe0.8Ni0.2-BC prepared with Fe/Ni molar being 8:2 exhibited the best PDS activation efficiency toward TC degradation, with 97.01% of TC being removed in 15 min. Combining with the electron paramagnetic resonance (EPR), reactive oxygen species quenching, and electrochemical tests, the direct electron transfer (DET) and singlet oxygen accounted for TC degradation in the Fe0.8Ni0.2-BC activating PDS system. Because of that, the Fe0.8Ni0.2-BC had satisfactory resistance to inorganic anions and natural organic matters (NOMs). Based on the structure-activity relationship, it was found that more Fe0 and pyrrolic N formation in FeNi alloys than single Fe or Ni embedding in BC facilitated in more PDS adsorption, thus more PDS* complex formation on the surface of catalysts to boost the TC degradation through DET mechanism. Moreover, Fe0.8Ni0.2-BC possessed trace Fe and Ni leaching, satisfactory stability, and easy recycling via magnetic separation. This study not only offers new insights for discriminating the catalytic active sites of biochar embedded bimetallic alloys catalysts activating PDS but also developed cost-effective and environment friendly catalysts for high-efficiently remove antibiotics via PS-AOPs.

Boosting the selective catalytic pyrolysis of plastic waste polylactic acid to monomer

Polylactic acid (PLA), as the most popular biodegradable polymers, has considered as a potential substitute for the petroleum-based plastics, but its large-scale applications are still limited because of lacking advisable wastes management strategies. Herein, we report a heterogeneous bimetallic FeNi catalyst for the selective catalytic pyrolysis of PLA to monomer under the isothermal temperature, solvent-free conditions. A series of Fe-based catalysts were prepared with a view to facilitate lactide conversion and improve its selectivity by tuning the properties of all Fe species. The optimal catalyst Fe10Ni1 @NC shows excellent catalytic performance with a 73% yield of lactide, which is mainly attributed to the “synergistic effect” between all Fe species sites and FeNi alloys and the basic of N-dope carbon matrix. It’s discovered that Fe/Fe,C/Fe3O4 sites are beneficial for the cleavage of ester linkages, and the FeNi alloys formed by introducing low amounts of Ni to Fe sites show better selectivity for the ring cyclization step. This work not only develops the pyrolysis methods of biodegradable plastic wastes to obtain the high-value chemicals and also contributes toward a circular economy.

Elastic constants of equiatomic Fe–Ni Invar alloy single crystal

In a disordered fcc structure, the equiatomic Fe–Ni alloy is of great interest as a soft magnetic Invar alloy with a near zero or low thermal expansion coefficient. In the L10 ordered phase, it is of interest as a potential high-performance permanent magnet alloy. In this work, the first detailed measurements of the elastic constants in a [001]-oriented Fe-50 at. % Ni alloy single crystal under a no magnetic field condition were made using the resonant ultrasound spectroscopy technique. The elastic constants measured allow one to understand the nature of atomic bonding in a material and the mechanical response to applied stress. The single crystal sample having a rectangular parallelepiped shape was prepared from a single crystal grown using the vertical Bridgman technique. The elastic constants C11, C12, and C44 were obtained from the resonant frequencies observed over a frequency range of 100–900 kHz. Using these C11, C12, and C44 values, Young’s modulus, shear modulus, bulk modulus, and Poisson’s ratio were calculated to be 99.1 GPa, 73.4 GPa, 176.7 GPa, and 0.20, respectively. The large anisotropy factor of 3.29 highlights the strong directional dependence of the material’s mechanical behavior.

Electrodeposition of Fe-Ni Alloy Films having Invar Compositions with Fe3+ as the Sole Iron Source

Fe-Ni alloy films with invar alloy compositions were electrodeposited from a stable citrate bath containing trivalent iron ions (Fe3+) as the sole iron source. This bath was prepared based on determining the equilibrium constants for acid dissociation, complex formation and precipitation reactions. Electrodeposition was conducted under galvanostatic conditions at 25 °C without agitation and an investigation was carried out into the effects of pH and current density on the composition and microstructure of the films. The results showed that ferric hydroxide (Fe(OH)3), which is normally poorly soluble, did not precipitate after electrodeposition. Fe-Ni alloy films containing 31‒42 mass% Ni (including Fe-36 mass% Ni) were formed with a current efficiency of approximately 70%. The films were smooth and were made up of grains with sub-micron sizes, although some cracks were observed. Fe and Ni were distributed homogeneously throughout the films and the Fe-Ni solid solutions exhibited both face-centered cubic and body-centered cubic structures.

Application of Various Materials With Negative Saturation Magnetostriction to Vibration Power Generation

Various materials with negative saturation magnetostriction were applied to a U-shaped unimorph device for vibration power generation using inverse magnetostrictive effect. When an fcc Fe-Ni alloy with the positive saturation magnetostriction was attached as an inverse magnetostrictive material on the front side of a U-shaped frame, larger values of the open-circuit voltage <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">op</sub> were obtained in comparison with that of the frame core device without a sample. However, when an fcc Ni metal with the negative saturation magnetostriction was attached on the front side of the U-shaped frame, its <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">op</sub> value was almost same as that of the frame core device. Larger <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">op</sub> values were obtained by attaching the fcc Ni metal on the back side of the U-shaped frame. Similar characteristics were observed in the devices using a bcc Fe metal and an hcp Co metal with negative saturation magnetostriction. Therefore, the back side setting is effective for the application of materials with negative saturation magnetostriction to the U-shaped unimorph device.

A Phase Field Study of the Influence of External Loading on the Dynamics of Martensitic Phase Transformation

An elastoplastic phase field model was employed for simulations to investigate the influence of external loading on the martensitic phase transformation kinetics in steel. The phase field model incorporates external loading and plastic deformation. During the simulation process, the authenticity of the phase field model is ensured by introducing the relevant physical parameters and comparing them with experimental data. During the calculations, loads of various magnitudes and loading conditions were considered. An analysis and discussion were conducted concerning the volume fraction and phase transition temperature during the phase transformation process. The simulation results prominently illustrate the preferential orientation of variants under different loading conditions. This model can be applied to the qualitative phase transition evolution of Fe-Ni alloys, and the crystallographic parameters adhere to the volume expansion effect. It is concluded that uniaxial loading promotes martensitic phase transformation, while triaxial compressive loading inhibits it. From a dynamic perspective, it is demonstrated that external uniaxial loading accelerates the kinetics of martensitic phase transformation, with uniaxial compression being more effective in accelerating the phase transformation process than uniaxial tension. When compared to experimental data, the simulation results provide evidence that under the influence of external loading, the martensitic phase transformation is significantly influenced by the applied load, with the impact of external loading being more significant than that of plastic effects.

Design strategy for high-entropy alloys with enhanced microstructural stability and mechanical properties for high-temperature applications

The use of AlCoCrFeNi high-entropy alloy as high-temperature structural materials is limited because of their phase instability. To address this, we designed Co-free Al–Cr–Fe–Ni alloys with spinodal structures composed of disordered body-centered cubic (BCC) (A2) and ordered BCC (B2) phases. The effect of Al and Ni content on the phase fractions and that of the Cr content on the microstructure and B2 precipitate size were evaluated. The composition of the alloy was optimized to enhance its microstructural stability and room-temperature machinability. Finally, Al13.6Cr(x)Fe(75.2-x)Ni11.2 alloys were designed and investigated for their phase stability and mechanical properties at both ambient and elevated temperatures. The fabricated Al13.6Cr(x)Fe(75.2-x)Ni11.2 alloys exhibited adequate phase stability at high temperatures. Particularly, as the Al13.6Cr13.3Fe61.9Ni11.2 (13Cr) alloy exhibited ductility of 1.3 % at 298 K, it can be a potential candidate as a high-temperature structural material. These findings suggest a promising design strategy for high-entropy alloys.

High La/Sr ratio in La0.67Sr0.33Fe0.67Ti0.33O3-δ cathode induced a controlled Fe0 exsolution for CO2 electrolysis

This study aimed at improving electrocatalytic activity of solid oxide electrolysis cell (SOEC) cathode via in-situ exsolved nanoparticles. La0.67Sr0.33Fe0.67Ti0.33O3-δ (LSFT) and La0.67Sr0.33Fe0.6Ni0.067Ti0.33O3-δ (LSFNT-67) cathodes with a La/Sr ratio about 2.0 showed the exsolution of Fe0 and FeNi3 alloy nanoparticles, respectively, under a reducing atmosphere. The SOEC with LSFT of electrocatalysis is better than LSFNT-67 at 800 °C for direct electrolysis of CO2, the current density of LSFT and LSFNT-67 reach − 0.54 A cm−2 and − 0.29 A cm−2, respectively, and the Faradaic efficiency is close to unity during the 25 h′ durability under a − 1.3 V bias. The better cell performance for the cell with LSFT than LSFNT-67 could be related to the larger <FeO6 > distortion and the less amount of insulating LaSrGa3O7 in the former, causing its unexpectedly larger quantity of metal exsolution and electron conduction for more active reaction sites for CO2 activation. This work demonstrated that apart from thermodynamic consideration, steric effect of the B site cation could be important for the exsolution of metal particles from a perovskite with high La/Sr ratio and the resultant electrocatalysis of CO2 electrolysis.

Behavior of Platinum-Group Elements during Hydrous Metamorphism: Constraints from Awaruite (Ni3Fe) Mineralization

Abstract Natural Fe-Ni alloys are common in meteorites and, presumably, the Earth’s core, where they host significant platinum-group elements (PGE). However, little is known on PGE concentrations in hydrothermal or metamorphic Fe-Ni alloys (i.e., awaruite Ni3Fe) from terrestrial rocks. In this work, we examine the geochemistry of awaruite and related minerals from several placer deposits sourced from the suprasubduction ophiolitic (Kamchatsky Mys, Karaginsky Island, and Mamet) and Ural-Alaskan (Galmoenan) complexes of Kamchatka and the Koryak Highlands (Far East Russia) in order to assess the abundance of PGE in awaruite and constrain their mobility under metamorphic and hydrothermal conditions. Studied awaruite from ophiolitic and Ural-Alaskan type complexes formed via desulfurization of pentlandite during serpentinization. Three groups of platinum-group minerals (PGMs) are associated with awaruite from Kamchatsky Mys: (1) Pt-Fe alloys such as ferronickelplatinum (Pt2FeNi) or unnamed Ni2FePt alloys; (2) Os-Ir-Ru alloys of various composition; (3) Pd-Sb minerals which form together with serpentine during hydrothermal alteration. Despite the abundance of PGM inclusions, no significant PGE concentrations were measured in awaruite from the Kamchatsky Mys, Karaginsky Island, or Mamet ophiolites. In contrast, pentlandite relicts in awaruite from placers related to the Galmoenan Ural-Alaskan type complex contain exceptionally high, previously unreported, Os (up to 540 ppm). Awaruite that forms on behalf of this pentlandite does not show any significant Os enrichment. Rare Galmoenan awaruite analyses yield up to 3 ppm Pd. The new data are not in complete accordance with previous studies that reported relatively high (up to first 10 ppm) PGE content in awaruite. We attribute this to low PGE concentration in precursor sulfides and preferential partitioning of PGE into discrete secondary PGM within awaruite. Nevertheless, abundant inclusions of secondary PGM in awaruite provide evidence of PGE mobility during metamorphic and hydrothermal alteration of ultramafic rocks.

Analysis of the mechanism of the effect of N–H–O impurities on diamond growth under HPHT

In this work, diamond crystals were synthesized with N–H–O impurities by the temperature gradient method (TGM) under high pressure and high temperature (HPHT) conditions using FeNi alloy as the metal solvent (MS). The results indicated that the spontaneous nucleation rate and proportion, growth characteristics, surface growth texture, and the impurity concentration of diamond crystals changed drastically upon changing the impurity content in the system. Mutual diffusion between the MS and carbon source (CS) was also blocked, which seriously inhibited the growth rate of diamond crystals. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses corroborated that the zero-valent iron (Fe0) and nickel (Ni0) contents declined after N–H–O impurities were introduced. The newly formed graphite can be found in the MS, but the ferric carbide disappears. XPS also confirmed shifts in the binding energy of FeNi MS peaks, more iron oxide and nickel oxide were identified in MS, hindering the mass transfer process. CO and NO were absorbed on the surface of MS, which hindered the surface processes of diamond growth. The formation of intermediates (Fe3C) was impeded during diamond growth and blocked the spontaneous nucleation of diamond. All of these phenomena contributed to a poor growth rate and changed the surface growth process of diamond crystals.

О МЕХАНИЗМАХ ОБРАЗОВАНИЯ НАНОСТРУКТУРНЫХ ЭЛЕКТРОЛИТИЧЕСКИХ ПОКРЫТИЙ Fe-Ni, Co-Mn, Ni-Cr С ФУНКЦИОНАЛЬНЫМИ СВОЙСТВАМИ

The evolution of modern industry is impossible without the development of new materials and technologies. Nanostructured coatings, in particular electrolytic coatings, are among the most demanded in mechanical engineering. The purpose of this work was to study the different mechanisms of obtaining Fe-Ni, CoMn, Ni-Cr galvanic alloys and their relationship with the specified universal physical and mechanical properties. Fe-Ni alloy is characterized by high microhardness and corrosion resistance in sea water, low cold brittleness; Co-Mn – by a specified phase composition (α-Co &gt;&gt; α-Mn, amorphous and metastable phase Co(OH)2); Ni-Cr – by high coating microhardness, specified phase composition. The main methods of production: high-frequency alternating current for Fe-Ni and Co-Mn alloys; introduction of a special additive (carbamide or H-acid) for Ni-Cr alloy. The main mechanisms are: Fe-Ni due to phase transition α-Fe ε-Fe; Co-Mn by means of high-frequency alternating current and carbamide addition, providing a specified phase composition; Ni-Cr by means of stationary method of addition of H-acid (high-chromium alloy of 68 mass percent of Cr) and carbamide (low-chromium alloy of 25 mass percent of Cr). Recommended uses for electroplating: Fe-Ni – for protection of oil and gas production equipment in the Arctic; CoMn – in modulation systems and as a nanocatalyst in the Fischer-Tropsch synthesis reaction; Ni-Cr – for corrosion-resistant protective coatings in petrochemistry and for resistive elements.

Pyrochlore@PBA derived electrocatalyst containing Ru nanoparticle and NiFe alloy for the oxygen evolution and reduction reactions

Developing enhanced electrocatalysts for the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) is essential for commercializing green energy technologies, such as Zn–air batteries. In this study, a uniquely designed metal catalyst–support material composite was synthesized using a Prussian blue analogue (PBA) and Y2Ru2O7 (YRO) pyrochlore for Zn-air battery. P–S-doped Ru nanoparticles and PBA-derived NiFe alloys anchored on the YRO pyrochlore (YRO@NiFe/Ru-PS) were synthesized in one pyrolysis process via in situ exsolution. The electronic structure of the Ru and NiFe particles was tailored by the pyrochlore support and P–S dual doping, which decreased the energy barrier for the catalytic reaction. YRO@NiFe/Ru-PS exhibited outstanding OER (overpotential = 241 mA/cm2; Tafel slope = 36 mV/dec) and ORR (half-wave potential = 0.83 V; Tafel slope = 65 mV/dec) performances. Furthermore, it also exhibited high performance in Zn–air battery applications (power density = 112 mW/cm2). This paper proposes an efficient and unique design strategy for developing OER/ORR bifunctional electrocatalysts.

Nanofibrous perovskite ceramics with in-situ exsolved Ni3Fe alloy nanoparticles for catalytic CO2 methanation

Exsolution is a promising method to prepare highly-dispersed and stable nanocatalysts, while exsolution efficiency is limited by the high temperature crystallization of parent perovskite ceramics, which leads to the low surface area of parent oxides for exsolution. The fibrous structure of ceramics shows highly-thermal stability, and this study employed the thermally-stable structure to realize the high efficiency of exsolved nanocatalysts from perovskites. Sr0.95Ti0.3Fe0.55Ni0.15O3-δ nanofibrous perovskites catalysts were prepared by electrospinning and subsequent calcination and reduction. The amount of exsolved Ni3Fe alloy nanoparticles increased with calcination temperature up to 1075 °C while the catalysts retained the nanofibrous structure. Further increasing calcination temperature to 1100 °C caused catalyst agglomeration. The Ni dissolution was also optimized by tuning the amount of Ni-doping to maximize catalyst activity. The nanofibrous catalysts demonstrated high and stable performance in CO2 methanation, and achieved the CO2 conversion and CH4 selectivity of 70.5% and 94.4% at 450 °C. Therefore, the merits of exsolution method have been realized over the nanofibrous perovskite catalysts.

Tailoring of electromagnetic properties of arc-produced carbon-coated FeNi alloy nanocapsules for highly efficient microwave absorption

Due to the growing harm of electromagnetic radiation, it is extremely urgent to develop high-efficiency microwave absorbers with tunable electromagnetic properties. Herein, a simple strategy for synthesizing hetero-atoms (sulfur) doped carbon-coated FeNi alloy nanocapsules (FeNi@C(Sx) NCs) by DC arc-discharge plasma was demonstrated. The hetero-interface between the FeNi alloy core and the graphitic shell induce interfacial polarization was found. Meantime, many defects produced by substitutional sulfur atoms in the graphitic shell facilitated dipole polarization and conduction loss. Besides, the multiple magnetic resonance produced by FeNi magnetic alloys worked together to optimize impedance matching. The excellent microwave absorption performance was attributed to the core-shell structure, dipole and interface polarizations, as well as favorable impedance matching. Importantly, the first-principles calculation was applied to prove the charge transfer and polarization process. The minimum reflection loss (RL) can reach up to −50.3 dB at a thickness of 1.6 mm.

Interstitial atom-doped NiFe alloy as pre-catalysts boost direct seawater oxygen evolution

NiFe-based materials are excellent OER electrocatalysts. However, it is difficult to stabilize anions and cations during reconstruction, which also leads to the problem of high valence metals at low levels and poor stability in direct seawater. Herein, we propose the strategy of using interstitial P atom-doped NiFe alloys (P4.8-NiFe ANs-400) as pre-catalysts to stabilize anions and cations, thereby promoting the formation of abundant high-valent metal species and excellent activity and stability in direct seawater. The reconstructed P4.8-NiFe ANs-400 catalyst generates a large amount of high-valence transition metal Ni4+, which contributed to its low overpotential (214 mV) and long-term stability (100 h) in a seawater electrolyte at 100 mA cm−2. Experiments and theoretical calculations show that the interstitially doped P atoms share the charge around the Fe and the active Ni sites, optimizing the free energy of the OER intermediate and making the chlorine evolution reaction (CER) difficult to proceed.

B-Site Super-Excess Design Sr2V0.4Fe0.9Mo0.7O6-δ-Ni0.4 as a Highly Active and Redox-Stable Solid Oxide Fuel Cell Anode.

In-situ exsolution type perovskites as solid oxide fuel cell (SOFCs) anode materials have received widespread attention because of their excellent catalytic activity. In this study, excessive NiO is introduced to the Sr2V0.4Fe0.9Mo0.7O6-δ (SVFMO) perovskite with the B-site excess design, and in-situ growth of FeNi3 alloy nanoparticles is induced in the reducing atmosphere to form the Sr2V0.4Fe0.9Mo0.7O6-δ-Ni0.4 (SVFMO-Ni0.4) composite anode. Here, with H2 or CH4 as SOFCs fuel gas, the formation of FeNi3 nanoparticles further enhances the catalytic ability. Compared with SVFMO, the maximum power density (Pmax) of Sr2V0.4Fe0.9Mo0.7O6-δ-Ni0.4 (SVFMO-Ni0.4) increases from 538 to 828 mW cm-2 at 850 °C with hydrogen as the fuel gas, and the total polarization resistance (RP) decreases from 0.23 to 0.17 Ω cm2. In addition, the long-term operational stability of the SVFMO-Ni0.4 anode shows no apparent performance degradation for more than 300 h. Compared with SVFMO, the Pmax of SVFMO-Ni0.4 increases from 138 to 464 mW cm-2 with methane as fuel gas, and the RP decreases from 1.21 to 0.29 Ω cm2.

Direct CH4–CO2 solid oxide fuel cells combined with Li-doped perovskite dry reforming catalysts for high efficiency power generation

Direct CH4–CO2 solid oxide fuel cells (SOFC) have attracted considerable attention due to their potential for high-efficiency power generation with low environmental impact. However, carbon deposition on Ni-based cermet anodes remains a critical challenge, leading to performance degradation. In this study, we propose a novel approach to address this issue by using a Li-doped perovskite, (La0.75Sr0.25)0.95Li0.1Cr0.5Fe0.4Ni0.1O3-δ (LSLCFN), as an exsolution system and a dry reforming catalyst for SOFCs. The LSLCFN catalyst exhibits enhanced carbon dioxide adsorption capacity, effectively reducing carbon deposition on the anode surface. In addition, the incorporation of Ni–Fe alloy nanoparticles facilitates dissolution in a reducing atmosphere and exhibits remarkable stability in the presence of carbon dioxide. Anode-supported single cells incorporating a LSLCFN-Ce0.9Gd0.1O2–δ(LSLCFN-GDC) composite as the anode active reforming layer exhibit excellent electrochemical performance when operated with both H2 and CH4–CO2 fuels. The peak power densities reach 904.86 and 825.37 mW cm−2 at 800 °C, respectively. Furthermore, the LSLCFN-GDC reforming layer maintains stable performance during the dry reforming of a 50%CH4–50%CO2 fuel mixture for 100 h at 700 °C, with negligible carbon deposition. These results highlight the effectiveness of employing a dry reforming catalyst to enhance CH4–CO2 reforming and optimize electrochemical performance for efficient energy conversion in SOFCs.