Bimetallic Systems Research Articles

Enforcing Metal-Arene Interactions in Bulky p-Terphenyl Bis(anilide) Complexes of Group 2 Metals (Be-Ba): Potential Precursors for Low-Oxidation-State Alkaline Earth Metal Systems.

An extremely bulky p-terphenyl bis(aniline), p-C6H4{C6H4[N(H)TCHP]-2}2 (TCHP = 2,4,6-tricyclohexylphenyl) TCHPTerphH2, has been developed. Deprotonation of a less bulky analogue, DipTerphH2 (Dip = 2,6-diisopropylphenyl), with BePh2 affords the bimetallic system, [(BePh)2(μ-DipTerph)] 1. Treating either TCHPTerphH2 or DipTerphH2 with Mg{CH2(SiMe3)}2 gives the monomeric bis(anilide) complexes [Mg(ArTerph)] (Ar = Dip 2, TCHP 3) which display rare examples of η6-arene coordination to the metal center. Treating 2 with THF leads to partial dissociation of the Mg···arene interaction and formation of [Mg(DipTerph)(THF)] 4. Reactions of the bis(aniline)s with the group 2 metal amides [M{N(SiMe3)2}2] afford dimeric, structurally analogous compounds [{M(ArTerph)}2] (Ar = Dip, M = Ca 5, Sr 6, Ba 7; Ar = TCHP, M = Ca 8, Sr 9, Ba 10) which display intermolecular M···arene interactions in the solid state. Computational studies have shown that the intramolecular M···η6-arene interactions in models of the ether-free metal bis(anilide) compounds are largely electrostatic in nature. Reductions of these compounds with alkali metals led to mixtures of unidentified products.

Inverse problems in resonant ultrasound spectroscopy based on spectra perturbation

In RUS, the fit between the experimental resonant spectrum and the result of the inversion procedure is usually worse than the inaccuracy of the experimental measurement of the resonant frequencies. Thus, it can be problematic to extract any valuable information from slight perturbation of experimental spectra, where the experimental frequency shift falls well below the accuracy of this fit. However, the inverse procedure can be reformulated and instead of fitting the resonant frequencies itself, it can be based on the direct fitting of the frequency perturbations. In this contribution, we show two examples of the use of this approach (i) quantitative RUS evaluation of the elasticity of micrometric and submicrometric surface layers from frequency differences measured before and after layer deposition [1] and (ii) in situ characterization of the thermal degradation of the bonding layer in a bimetallic system [2]. [1] Thomasová M. et al. Young's moduli of sputter-deposited NiTi films determined by resonant ultrasound spectroscopy: Austenite, R-phase, and martensite (2015) Scripta Materialia, 101, pp. 24–27. [2] Janovská M. et al Characterization of bonding quality of a cold-sprayed deposit by laser resonant ultrasound spectroscopy (2020) Ultrasonics, 106, art. no. 106140.

Green Synthesis and Efficient Adsorption: Na-X Zeolite vs. C/Mn/SiO2 Composite for Heavy Metals Removal.

The studies aimed to test the adsorption capacity of two silica-enriched porous materials, synthetic Na-X zeolite and Mn-containing carbon composite, towards Pb(II) and Zn(II) ions in single and mixed systems and in the presence of diclofenac (DCF) and (or) poly(acrylic acid) (PAA). The synthetic zeolite was characterized by a well-developed surface area of 728 m2/g and a pore diameter of 1.73 nm, while the carbon composite exhibited 268 m2/g and 7.37 nm, respectively. Na-X was found to be more efficient than the carbon composite (75-212 mg/g) in adsorbing heavy metal ions in both single and bimetallic systems (322-333 mg/g). In turn, the C/Mn/SiO2 composite was more effective in removing Pb(II) ions from the systems that simultaneously contained DCF or PAA (480 and 476 mg/g, respectively). The Na-X zeolite demonstrated the greatest stability in all the systems studied. The highest stability was observed in the DCF + Pb(II) mixture, in contrast to the carbon composites where the stability was much lower. To evaluate the possibility of regeneration of the solids, HCl proved to be the best desorbent for heavy metal ions (efficiency of 99%). In general, both adsorbents offer promising potential for solving environmental problems.

Intertwining of Localized (d) and Delocalized (π) Spins in Magnetically Frustrated Two-Dimensional Metal-Organic Frameworks.

Two-dimensional metal-organic frameworks (2D MOFs) are emerging as a new class of multifunctional materials for diversified applications, although magnetic properties have not been widely explored. The metal ions and organic ligands in some of the 2D MOFs are arranged in the well-known Kagome lattice, leading to geometric spin frustration. Hence, such systems could be the potential candidates to exhibit an exotic quantum spin liquid (QSL) state, as was observed in Cu3(HHTP)2 (HHTP = hexahydroxytriphenylene), with no magnetic transition down to 38 mK. Hereto, we have investigated the spin intertwining in a bimetallic 2D MOF system, M3(HHTP)2 (M = Cu/Zn), arising from the localized (d-electron) and delocalized (π-electron) S = 1/2 spins from the Cu(II) ions and the HHTP radicals, respectively. The origin of the spin frustration (down to 5K) was critically examined by varying the metal composition in bimetallic systems, CuxZn3-x(HHTP)2 (x = 1, 1.5, 2), containing both S = 1/2 and S = 0 spins. Additionally, to gain a deeper understanding, we studied the spin interaction in the pristine Zn3(HHTP)2 system containing only S = 0 Zn(II) ions. In view of the quantitative estimate of the localized and delocalized spins, the d-π spin correlation appears essential in understanding the unusual magnetic and/or other physical properties of such hybrid organic-inorganic 2D crystalline solids.

Unraveling the Chirality Transfer from Circularly Polarized Light to Single Plasmonic Nanoparticles.

Due to their broken symmetry, chiral plasmonic nanostructures have unique optical properties and numerous applications. However, there is still a lack of comprehension regarding how chirality transfer occurs between circularly polarized light (CPL) and these structures. Here, we thoroughly investigate the plasmon-assisted growth of chiral nanoparticles from achiral Au nanocubes (AuNCs) via CPL without the involvement of any chiral molecule stimulators. We identify the structural chirality of our synthesized chiral plasmonic nanostructures using circular differential scattering (CDS) spectroscopy, which is correlated with scanning electron microscopy imaging at both the single-particle and ensemble levels. Theoretical simulations, including hot-electron surface maps, reveal that the plasmon-induced chirality transfer is mediated by the asymmetric distribution of hot electrons on achiral AuNCs under CPL excitation. Furthermore, we shed light on how this plasmon-induced chirality transfer can also be utilized for chiral growth in bimetallic systems, such as Ag or Pd on AuNCs. The results presented here uncover fundamental aspects of chiral light-matter interaction and have implications for the future design and optimization of chiral sensors and chiral catalysis, among others.

Unraveling the Chirality Transfer from Circularly Polarized Light to Single Plasmonic Nanoparticles

AbstractDue to their broken symmetry, chiral plasmonic nanostructures have unique optical properties and numerous applications. However, there is still a lack of comprehension regarding how chirality transfer occurs between circularly polarized light (CPL) and these structures. Here, we thoroughly investigate the plasmon‐assisted growth of chiral nanoparticles from achiral Au nanocubes (AuNCs) via CPL without the involvement of any chiral molecule stimulators. We identify the structural chirality of our synthesized chiral plasmonic nanostructures using circular differential scattering (CDS) spectroscopy, which is correlated with scanning electron microscopy imaging at both the single‐particle and ensemble levels. Theoretical simulations, including hot‐electron surface maps, reveal that the plasmon‐induced chirality transfer is mediated by the asymmetric distribution of hot electrons on achiral AuNCs under CPL excitation. Furthermore, we shed light on how this plasmon‐induced chirality transfer can also be utilized for chiral growth in bimetallic systems, such as Ag or Pd on AuNCs. The results presented here uncover fundamental aspects of chiral light‐matter interaction and have implications for the future design and optimization of chiral sensors and chiral catalysis, among others.

Vinylic C-H Activation of Styrenes by an Iron-Aluminum Complex.

The oxidative addition of sp2 C-H bonds of alkenes to single-site transition-metal complexes is complicated by the competing π-coordination of the C═C double bond, limiting the examples of this type of reactivity and onward applications. Here, we report the C-H activation of styrenes by a well-defined bimetallic Fe-Al complex. These reactions are highly selective, resulting in the (E)-β-metalation of the alkene. For this bimetallic system, alkene binding appears to be essential for the reaction to occur. Experimental and computational insights suggest an unusual reaction pathway in which a (2 + 2) cycloaddition intermediate is directly converted into the hydrido vinyl product via an intramolecular sp2 C-H bond activation across the two metals. The key C-H cleavage step proceeds through a highly asynchronous transition state near the boundary between a concerted and a stepwise mechanism influenced by the resonance stabilization ability of the aryl substituent. The metalated alkenes can be further functionalized, which has been demonstrated by the (E)-selective phosphination of the employed styrenes.

Visible-Light-Mediated Bimetal-Catalyzed meta-Alkylation of Arenes.

A mild approach to the visible-light-mediated bimetal-catalyzed meta-alkylation of arenes has been accomplished. The regioselective meta-alkylation is realized by a bimetallic ruthenium-palladium system. Ruthenium acts as a catalyst for the directing effect and as a photosensitizer, while the cocatalyst palladium behaves as a catalyst for the generation of fluoroalkyl radicals. This reaction not only is suitable for two-component meta-fluoroalkylation of arenes but can also be extended to three-component reactions to achieve bifunctionalization of olefins.

Fe-Ni porphyrin/mesoporous titania thin film electrodes: a bioinspired nanoarchitecture for photoelectrocatalysis.

Porphyrin and porphyrinoid derivatives have been extensively studied in the assembly of catalysts and sensors, seeking biomimetic and bioinspired activity. In particular, Fe and Ni porphyrins can be used for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) by immobilization of these molecular catalysts on semiconductor materials. In this study, we designed a hybrid material containing a crystalline mesoporous TiO2 thin film in which the catalytic centres are Ni-porphyrin (NiP), Fe-porphyrin (FeP), and a NiP/FeP bimetallic system to assess whether the coexistence of both metalloporphyrins improves the OER activity. The obtained photoelectrodes were physicochemically and morphologically characterized through high-resolution FE-SEM images, UV-vis and Raman spectroscopies, cyclic voltammetry, and impedance measurements. The results show a differential behavior of the mono- and bimetallic porphyrin systems, where the Fe(iii) centre in FeP may increase the acidity and lower the reduction potential of the Ni2+/3+ couple when co-deposited with NiP leading to an improved photoelectrochemical water-oxidation performance. We have validated the cooperative effect of both metal complexes within this novel system, where the μ-peroxo-bridged interaction between Fe and Ni is integrated into a supramolecular heterometallic structure of porphyrins.

Reactive multilayer nanofilms: time of scientific and technological maturity

The review presents the results of recent research and the latest developments in the field of reactive multilayer nanofilms (RMNFs), which were first obtained in the mid-1990s and have now formed a special class of energetic materials produced by layer-by-layer deposition. This class includes M/Al systems (M = Ni, Ti, Zr, Pt, Pd), other bimetallic systems (Ni/Ti, etc.), M/Nm systems (M = Ti, Zr, Nm = Si, B, C) and thermite systems (Al/CuO, etc.) and continues to expand. The emergence of RMNFs stimulated the creation of new experimental diagnostic methods and computer models for fast physicochemical processes. It is shown that the reaction in the front of a self-propagating exothermic wave occurs in a time of the order of microseconds, which is determined by the rate of dissolution of a solid reactant in the melt of the second, low-melting reactant (usually Al) and by the rate of liquid-phase diffusion. The unique properties of reaction waves in RMNFs are used in novel technologies for bonding dissimilar materials.<br> The bibliography inncludes 160 references.

Temperature-driven evolution of ceria-zirconia-supported AuPd and AuRu bimetallic catalysts under different atmospheres: insights from IL-STEM studies.

The evolution of the structure and composition of the system of particles in two Ce0.62Zr0.38O2-supported bimetallic catalysts based on Au and a 4d metal (Ru or Pd) under high temperature conditions and different reducing and oxidizing environments has been followed by means of Identical Location Scanning Transmission Electron Microscopy (IL-STEM). As an alternative to in situ microscopy, this technique offers valuable insights into the structural modifications occurring in chemical environments with the characteristics of a macro-scale reactor. By tracking exactly the same areas on a large number of metallic entities, it has been possible to reveal the influence of particle size and the nature of the redox environment on the temperature-driven mobilization of the different metals involved. Thus, oxidizing environments evidenced a much higher capacity to mobilize the three metals, preferentially Au. Moreover, the typical storage conditions (under air) of catalysts during the prolonged exposure time has been proved to induce significant modifications in these bimetallic systems, even at room temperature. Regardless of the type of redox environment, bimetallic systems showed better thermal resistance, which demonstrates a beneficial effect of the second metal. In summary, IL-STEM is an invaluable and complementary methodology for characterizing heterogeneous catalysts under realistic reaction conditions and is within the reach of most laboratories.

High-performance electrochemical immunosensor based on bimetallic gold/silver functionalized carbon spheres for CYFRA 21-1 detection and information protection.

Bimetallic nanomaterial-based systems have been widely utilized across various fields due to their remarkable expandability and flexibility, including nanomedicine, diagnostics, and molecular information technology. Here, we constructed an electrochemical immunosensor using bimetallic gold/silver functionalized carbon spheres (AuAg@CSs) and mesoporous silica nanoparticles (MSNs) for the sensitive determination of cytokeratin 19 fragment antigen 21-1 (CYFRA 21-1) and ensuring information protection for textual data. The AuAg@CSs demonstrated exceptional catalytic activity towards hydrogen peroxide, generating a significant current signal. The introduction of CYFRA 21-1 facilitated the binding of MSNs, thereby forming a sandwich-type electrochemical immunosensor that resulted in a notable decrease in current. Notably, the detection limit for CYFRA 21-1 was determined to be 31 fg mL-1, accompanied by high selectivity. Furthermore, extensive textual information can be encrypted and concealed within the current responses of the electrochemical nanosensing system. By establishing a threshold, these current signals can be represented as a series of binary strings, which can subsequently be segmented into shorter strings. Through information coding methods, these shorter binary strings can be assembled and decrypted, ultimately merging into meaningful textual content. This study promotes the synthesis and multifunctional application of bimetallic nanomaterials, providing innovative solutions to enhance the sensing sensitivity of electrochemical immunosensors and paving the way for advancements in molecular digitization.

Synergistic effects of the bimetallic Ni-Fe systems and their application in the reductive amination of polyether polyols.

We report the synthesis of xNi-yFe/γ-Al2O3 catalysts which were applied to the reductive amination of polypropylene glycol (PPG) for the preparation of polyether amine (PEA). The catalysts were characterized by N2-sorption, X-ray diffraction, H2-temperature programmed reduction, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy to reveal the synergistic effect of the bimetallic Ni-Fe-loaded catalysts. It was found that in the reductive amination of PPG to PEA, the conversion and product selectivity of the reaction were closely related to the types of active centers of the catalyst. In particular, the surface Ni0 content increased by adding Fe as a promoter, with a maximum Ni0 content on the 15Ni-7.5Fe/Al2O3 catalyst, which also led to the highest conversion rate (>99%). In addition, no deactivation was observed after three cycles of reaction carried out by the catalyst.

Accurate and interpretable representation of correlated electronic structure via Tensor Product Selected CI.

The task of computing wavefunctions that are accurate, yet simple enough mathematical objects to use for reasoning, has long been a challenge in quantum chemistry. The difficulty in drawing physical conclusions from a wavefunction is often related to the generally large number of configurations with similar weights. In Tensor Product Selected Configuration Interaction (TPSCI), we use a locally correlated tensor product state basis, which has the effect of concentrating the weight of a state onto a smaller number of physically interpretable degrees of freedom. In this paper, we apply TPSCI to a series of three molecular systems ranging in separability, one of which is the first application of TPSCI to an open-shell bimetallic system. For each of these systems, we obtain accurate solutions to large active spaces, and analyze the resulting wavefunctions through a series of different approaches including (i) direct inspection of the TPS basis coefficients, (ii) construction of Bloch effective Hamiltonians, and (iii) computation of cluster correlation functions.

Thermally Induced Surface Structure and Morphology Evolution in Bimetallic Pt-Au/HOPG Nanoparticles as Probed Using XPS and STM.

Bimetallic nanoparticles expand the possibilities of catalyst design, providing an extra degree of freedom for tailoring the catalyst structure in comparison to purely monometallic systems. The distribution mode of two metal species defines the structure of surface catalytic sites, and current research efforts are focused on the development of methods for their controlled tuning. In light of this, a comprehensive investigation of the factors which influence the changes in the morphology of bimetallic nanoparticles, including the elemental redistribution, are mandatory for each particular bimetallic system. Here we present the combined XPS/STM study of the surface structure and morphology of bimetallic Pt-Au/HOPG nanoparticles prepared by thermal vacuum deposition and show that thermal annealing up to 350 °C induces the alloying process between the two bulk-immiscible metal components. Increasing the treatment temperature enhances the extent of Pt-Au alloying. However, the sintering of nanoparticles starts to occur above 500 °C. The approach implemented in this work includes the theoretical simulation of XPS signal intensities for a more meticulous analysis of the compositional distribution and can be helpful from a methodological perspective for other XPS/STM studies of bimetallic nanoparticles on planar supports.

Synergistically catalytic regulation of surface chemistry on coal based needle coke by bimetallic interface for enhanced Li/Na storage

The oxygen functional groups (OFGs) on carbon surface are electrochemically active for rapid Li/Na storage, and always are introduced with environment-hazardous and time-consuming ways. Herein, the bimetallic synergistic effect between Fe and Ni metal nanoparticles is proved experimentally to promote the conversion from useless C–O groups to useful CO groups on the surface of needle coke (NC) greatly. In addition, the DFT calculations show that introducing second metals increase the active electrons of single metals, and the activity of transforming C–O bond to CO bond thus makes a difference in bimetallic systems. Among the modified samples, Fe/Ni-NC contains abundant CO groups, stripe like graphite domains, excellent electronic conductivity and large interlayer spacing. Therefore, Fe/Ni-NC anode shows the excellent capacities in half batteries (212/305.2 mA h g−1 after 1000/2000 cycles at 2.0/5.0 A g−1 in SIB/LIB) and full batteries (86/145 mA h g−1 in SIB/LIB at 0.05 A g−1 after 100 cycles), significantly better than other carbon materials. The work provides a practical and significant reference to regulate precisely the surface energy storage active sites of coal based carbon material, aiming at advanced SIB and LIB.

Gas-Phase CuPd Bimetallic Cluster-Modified Electrodes as Model Electrocatalysts for CO2 Conversion

Copper-based electrocatalysts possess the unique ability to convert CO2 to multicarbon products such as ethylene – a precursor in many industrial processes. However, their stability and product selectivity remain insufficient. A promising approach to overcome these shortcomings and design better CO2RR electrocatalysts is to tune Cu selectivity by forming bimetallic Cu-M systems [1] while establishing their detailed structure-selectivity relationship. To achieve this, we used laser ablation Cluster Beam Deposition (CBD) [2] to produce well-defined bimetallic cluster-modified electrodes [2]. More specifically, CuPd clusters with an original average size of 2.5 nm and mass loadings of 1-3 µg cm-2 were deposited onto a carbon support. To produce a model catalyst which allows the independent investigation of the electronic and geometric structural effects induced to Cu by the second element, a Cu0.9Pd0.1 composition was selected [3]. CuPd cluster-decorated electrodes were tested for CO2 electrolysis and methane (C1), and ethylene (C2) were found among the products. Observed from the electrocatalytic activity trends, the evolution of C2 products is correlated with the cluster mass loading. In addition, the cluster coverage has an effect on the onset of the competitive H2 evolution (HER); with the lowest cluster-loaded electrodes presenting more intense HER due to limited cluster coverage of the carbon substrate. High resolution (Scanning) Transmission Electron Microscopy ((S)TEM) coupled with Energy-dispersive X-ray spectroscopy (EDX), and X-ray Photoelectron Spectroscopy (XPS) analyses of the as-prepared cluster-modified electrodes, show that the clusters feature some degree of CuPd alloying in the ambient. CuPd cluster-based systems will then be investigated in-situ using X-ray absorption spectroscopy to unravel their structure-catalytic performance relationship.

Achieving Tunable Selectivity and Activity of CO2 Electroreduction to CO Via Bimetallic Silver-Copper Electronic Engineering

Electrocatalytic CO2 reduction reaction (E-CO2RR) provides a sustainable way to convert greenhouse gases into value-added chemicals and small-molecule fuels[1, 2]. However, the efficient production of a single product remains a challenge. To this end, we have constructed the Ag-Cu bimetallic system as an experimental platform to investigate the process of electronic effects on the selectivity and activity of CO products in more detail. Specifically, metallic Ag is used as the matrix and different levels of Cu (Ag, Ag99Cu1, Ag96Cu4, Ag70Cu30, Ag30Cu70, Cu) are added as modifiers of the 3d orbital electron density of the system to adjust the adsorption strength of *H (key intermediates for H2 formation), *COOH and *CO (the key intermediate of CO formation) intermediates. Combining the electrochemical test results with the DFT calculations, we obtain the following trends: The addition of trace amounts of Cu (Ag99Cu1, Ag96Cu4) can greatly enhance the catalytic potential of Ag for the selective production of CO products at low potentials, achieving near 100% selectivity for CO products (Ag96Cu4, -1V vs. RHE).The observed rate determining step of the reaction on Ag30Cu70 from CO2–*COOH to *COOH–*CO implies that adding too much Cu or leading to strong adsorption of *CO results in poisoning.It was observed that Ag96Cu4 had the optimum CO selectivity and Ag70Cu30 had the optimum CO activity current, which is different from previous concentrations on the same catalyst. (Figure 1a, b) We attribute the above findings to Ag96Cu4 effectively reducing the free energy of the formation of *COOH while maintaining a relatively high theoretical overpotential for hydrogen evolution reaction (HER), thus achieving the best CO selectivity (Figure 1c, d). While the Ag70Cu30 together activates the CO2RR and HER processes and shows relatively low formation energies of *COOH and *H, the compromised thermodynamic barrier and product selectivity allows for the best CO partial current density to be exhibited (Figure 1c, d). We believe that the electron effect will serve as an effective platform for screening selective and active catalysts. Figure1. a) FECO and b) jCO as a function of the proportion of Cu in AgxCu100-x series catalysts. c, d) The calculated free energy diagrams of CO2RR to CO and HER on fcc Ag (111), Ag96Cu4 (111), Ag70Cu30 (111), Ag30Cu70 (111) and Cu (111) surfaces at 0 V vs. RHE, respectively. Reference Grätzel, M., Nature 2001, 414 (6861), 338-344. DOI 10.1038/35104607.Zheng, Y.; Vasileff, A.; Zhou, X.; Jiao, Y.; Jaroniec, M.; Qiao, S.-Z., Journal of the American Chemical Society 2019, 141 (19), 7646-7659. DOI 10.1021/jacs.9b02124. Figure 1

Bimetallic Fenton-like Catalysts in the Remediation of Dyes

Remediation of organic dyes in natural waters is a significant environmental need under active study. This review analyzes bimetallic catalytic degradation systems that are based on the Fenton chemistry concept and that generate reactive oxygen species (ROS) as the agent of dye breakdown. Recently developed advanced oxidation processes (AOPs) take advantage of bimetallic heterogeneous catalysts to facilitate rapid rates and full degradation. Catalysts based on two metals including iron, copper, molybdenum, cobalt and magnesium are discussed mechanistically as examples of effective radical ROS producers. The reactive oxygen species hydroxyl radical, superoxide radical, sulfate radical and singlet oxygen are discussed. System conditions for the best degradation are compared, with implementation techniques mentioned. The outlook for further studies of dye degradation is presented.

Enhanced bonding strength of Al/Fe bimetal by Ni-based alloys Ni-based interlayer prepared by laser cladding technique

In the process of manufacturing aluminum/iron (Al/Fe) bimetal, improving the bonding strength was a crucial consideration. To achieve this goal, this study focused on two aspects: optimizing the composition of intermetallic compounds and modifying the stress state near the interface. The introduction of a Ni-based coating was investigated to accomplish these objectives. The incorporation of the Ni-based coating resulted in a transformation of the phase composition in the reaction layer from the brittle Al-Fe-Si phase to the mechanically superior Al-Fe-Ni phase. Furthermore, significant changes in the morphology of the reaction layer were observed, with the formation of blocky intermetallic compounds adjacent to the Al matrix on the continuous intermetallic phase side. These alterations effectively alleviated stress concentration at the interface, leading to an increase in the shear strength from 50.4 MPa to 117.4 MPa. The findings of this study demonstrated the positive role of the Ni-based coating in mitigating stress concentration at the interface and enhancing the bonding strength of the Al/Fe bimetallic system. By optimizing the phase composition and morphology of the reaction layer, the bonding capability at the interface was significantly improved.