Precision tuning of highly efficient Pt-based ternary alloys on nitrogen-doped multi-wall carbon nanotubes for methanol oxidation reaction

The electrochemical methanol oxidation is a crucial reaction in the conversion of renewable energy.To enable the widespread adoption of direct methanol fuel cells(DMFCs),it is essential to create and engineer catalysts that are both highly effective and robust for conducting the methanol oxidation reaction(MOR).In this work,trimetallic PtCoRu electrocatalysts on nitrogen-doped carbon and multi-wall carbon nanotubes(PtCoRu@NC/MWCNTs)were prepared through a two-pot synthetic strategy.The acceleration of CO oxidation to CO_(2) and the blocking of CO reduction on adjacent Pt active sites were attributed to the crucial role played by cobalt atoms in the as-prepared electrocatalysts.The precise control of Co atoms loading was achieved through precursor stoichiometry.Various physicochemical techniques were employed to analyze the morphology,element composition,and electronic state of the catalyst.Electrochemical investigations and theoretical calculations confirmed that the Pt_(1)Co_(3)Ru_(1)@NC/MWCNTs exhibit excellent electrocatalytic performance and durability for the process of MOR.The enhanced MOR activity can be attributed to the synergistic effect between the multiple elements resulting from precisely controlled Co loading content on surface of the electrocatalyst,which facilitates efficient charge transfer.This interaction between the multiple components also modifies the electronic structures of active sites,thereby promoting the conversion of intermediates and accelerating the MOR process.Thus,achieving precise control over Co loading in PtCoRu@NC/MWCNTs would enable the development of high-performance catalysts for DMFCs.

A comparative study on Sn macrosegregation behavior of ternary Al-Sn-Cu alloys prepared by gravity casting and squeeze casting

A comprehensive study on Sn macrosegregation behavior in ternary Al-Sn-Cu alloys was carried out by comparative analysis between gravity casting and squeeze casting samples.The microstructure and Sn distribution of the castings were characterized by metallography,scanning electron microscopy(SEM),energy-dispersive X-ray(EDX)spectroscopy,and a direct reading spectrometer.Results show that there are obvious differences in Sn morphology between gravity casting and squeeze casting alloys.Under squeeze casting condition,the grain size of the casting is smaller and the distribution ofβ(Sn)is uniform.This effectively reduces the segregation of triangular grain boundary as well as the segregation of Sn.The segregation types of Sn in gravity casting and squeeze casting samples are obviously different.The upper surfaces of gravity casting samples show severe negative segregation,while all the lower surfaces have positive segregation.Compared with gravity casting,squeeze casting solidifies under isostatic pressure.Due to the direct contact between the upper surface of the casting and the mold,the casting solidifies faster under higher undercooling degree and pressure.Consequently,the uniform distribution of Sn reduces the segregation phenomenon on the surface of the casting.

Growth morphology and evolution of quasicrystal in as-solidified Y-rich Mg-Zn-Y ternary alloys

A petal-like icosahedral quasicrystal with five branches,which is considered to be the representative morphology of the icosahedral quasicrystal,has been observed in the Y-rich Mg-Zn-Y ternary alloys. Moreover,the polygon-like morphology,another pattern of the icosahedral quasicrystal,has also been found in the Y-rich Mg-Zn-Y ternary alloys. The latter morphology results from the evolution of the former one. The growth mechanism of the petal-like morphology of the icosahedral quasicrystal was also discussed. Alloying composition,i.e.,Y element content,is a major factor inducing the morphology evolution of the icosahedral quasicrystal.

Influence of Ni on Cu precipitation in Fe Cu Ni ternary alloy by an atomic study

The early aging Cu precipitations in Fe-3%Cu and Fe-3%Cu-4%Ni ternary alloys are investigated by molecular dynamics （MD） simulations. The results show that the average size of Cu clusters in Fe-3%Cu-4%Ni alloy is larger than that in Fe-3%Cu alloy. The diffusion of Cu is accelerated by Ni according to the mean square displacement （MSD）. Furthermore, the whole formation process of Cu-rich clusters is analyzed in detail, and it is found that the presence of Ni promotes small Cu-rich clusters to be combined into big ones. Ni atoms prefer to stay at the combination positions of small clusters energetically due to a large number of the first nearest neighbor Cu-Ni interactions, which is verified by first-principles calculations based on density functional theory （DFT）.

Calculation of the Heat of Formation:Ternary Alloy System

A semi-empirical calculation of the heat of formation was applied to ternary system: La-Fe-Al,Fe-Ni-V and Cu-Pd-Si.The calculated values were compared with the experimental ones and the coincidence was satisfactory.This method is helpful to predict the stabilities of ternary compounds and solid solubility.

PREDICTION ON THE THERMODYNAMIC PROPERTIES OF TERNARY LIQUID ALLOYS BY MODIFIED COORDINATION EQUATION

The coordination numbers in the Molecular Interaction Volume Model can be calcu-lated from the common physical quantities of pure matters.A significant advantage ofthe model lies in its ability to predict the thermodynamic properties of ternary liqmdalloys using only the binary infinite dilute activity coefficients,and the predicted values are in good agreement with the experimental data of ternary liquid alloys,whichshows that the model is reliable,convenient and economic.

Liquid State Undercoolability and Crystal Growth Kinetics of Ternary Ni-Cu-Sn Alloys

The liquid state undercoolability and crystal growth kinetics of ternary Ni-5%Cu-5%Sn and Ni-10%Cu-10%Sn alloys are investigated by the glass fluxing method. In these two alloys, experimental maximum undercoolings of 304 K （0.18TL ） and 286K （0.17TL ） are achieved and the dendritic growth velocities attain 39.8 and 25.1 m/s, respectively. The transition of morphology from coarse dendrite into equiaxed structure occurs and the grain size of the a （Ni） phase decreases remarkably when the undercooling increases. Both the lattice constant and microhardness increase obviously with the enhancement of undercooling. The enrichment of Cu and Sn solute contents reduces the dendritic growth velocity, while enhances the lattice constant and microhardness of a （Ni） phase.

Realizing high-performance organic solar cells through precise control of HOMO driving force based on ternary alloy strategy

A good deal of studies have proven that effective exciton dissociation and fast hole transport can operate efficiently in non-fullerene organic photovoltaics(OPVs)despite nearly zero driving force.Even so,whether such a phenomenon is universal and how small the driving force can realize the best photovoltaic performance still require a thorough understanding.Herein,despite the zero driving force based on PM6:F8IC system,a maximum short-circuit current(J_(sc))of 23.0 mA/cm^(2) and high power conversion efficiency(PCE)of 12.2%can still be achieved.Due to the continuously adjustable energy levels can be realized in organic semiconducting alloys including F8IC:IT-4F and F8IC:Y6,the suitable third components can play the role of energy level regulator.Therefore,the HOMO energy level offset(DEHOMO(D A))from zero to 0.07 and 0.06 eV is accomplished in the optimized IT-4F and Y6 ternary devices.Consequently,both ternary devices achieved substantially increased PCE of 13.8%and Jsc of 24.4 and 25.2 mA/cm^(2),respectively.Besides,pseudo-planar heterojunction(PPHJ)devices based on alloyed acceptors through sequential spin-coating method further improve the photovoltaic performance.Our work puts forward the concept of energy level regulator and prove that the ternary alloy strategy has unique advantages and huge research potential in continuously adjusting the driving force.

Electrical Properties of GeTe-based Ternary Alloys

Ge_（50-x）Sb_xTe_（50） and Ge_（50-x）Bi_xTe_（50） ternary alloys were synthesized by vacuum melting at 1273 K with the starting materials of Ge, Bi, Sb, and Te. The lattice structures were analyzed based on X-ray diffraction patterns, which could all be indexed to R3m rhombic structure. Electrical properties measurements revealed that the Ge-Sb-Te ternary alloys were p-type semiconductors with high electrical conductivity of 4.5×10~5S？m^（-1） near room temperature. And the maximum electrical property was obtained at Ge_45Sb_5Te_50, with the power factor of 2.49×10^（-3）W？m^（-1）K^（-2） at 640 K. Due to the existence of secondary phases, the electrical conductivity of Ge-Bi-Te system was lower and Seebeck coefficient was higher comparing with those of Ge-Sb-Te system.

Simulation of Dendritic Growth with Melt Convection in Solidification of Ternary Alloys

A cellular automaton-lattice Boltzmann coupled model is extended to study the dendritic growth with melt convection in the solidification of ternary alloys. With a CALPHAD-based phase equilibrium engine, the effects of melt convection, solutal diffusion, interface curvature and preferred growth orientation are incorporated into the coupled model. After model validation, the multi dendritic growth of the Al-4.0 wt%Cu-1.0 wt%Mg alloy is simulated under the conditions of pure diffusion and melt convection. The result shows that the dendritic growth behavior, the final microstructure and microsegregation are significantly influenced by melt convection in the solidification.

Mechanical, electrical, and thermal properties of the directionally solidified Bi–Zn–Al ternary eutectic alloy

A Bi-2.0Zn-0.2A1 （wt%） ternary eutectic alloy was prepared using a vacuum melting furnace and a casting furnace. The samples were directionally solidified upwards at a constant growth rate （V= 18.4 μm/s） under different temperature gradients （G = 1.15-3.44 K/mm） and at a constant temperature gradient （G = 2.66 K/mm） under different growth rates （V= 8.3-500 μm/s） in a Bridgman-type directional so- lidification furnace. The dependence ofmicrostructure parameter （2） on the solidification parameters （G and V） and that of the microhardness （Hv） on the microstructure and solidification parameters were investigated. The resistivity （ρ） measurements of the studied alloy were per- formed using the standard four-point-probe method, and the temperature coefficient of resistivity （α） was calculated from the ρ-Tcurve. The enthalpy （AH） and the specific heat （Cp） values were determined by differential scanning calorimetry analysis. In addition, the thermal conductivities of samples, obtained using the Wiedemann-Franz and Smith-Palmer equations, were compared with the experimental results. The results revealed that, the thermal conductivity values obtained using the Wiedemarm-Franz and Smith-Palmer equations for the Bi-2.0Zn-0.2Al （wt%） alloy are in the range of 5.2-6.5 W/Km and 15.2-16.4 W/Km, respectively.

Characterization and corrosion studies of ternary Zn–Ni–Sn alloys

Nine distinct zinc-nickel-tin films with different compositions have been galvanostatically electrodeposited. The films have been characterized by scanning electron microscopy(SEM) and energy dispersive spectrometry(EDS). Their corrosion potentials and densities have been estimated using Tafel extrapolation. Next, the electrochemical behaviors of the films(deposited through the electrolytes containing 0, 6, 8, and10 g/L SnCl2?6H2O) have been examined based on cyclic voltammetry(CV) measurements. Further, these films have been immersed in 3.5 wt%Na Cl solution for 1 h, 1 d, 7 d, 14 d, 28 d, and 42 d followed by application of Tafel extrapolation and electrochemical impedance spectroscopy(EIS) tests on each aged sample. Finally, to analyze the morphologies and the compositions of the oxide films covering the surfaces of the 42-d aged films, FT-IR and SEM analyses have been performed. The results indicated that the Zn–Ni–Sn film produced through the bath including 6g/L SnCl2?6H2 O exhibits superior corrosion resistance because of the high Ni content in the presence of Sn that promotes the barrier protection capability of the deposit.

Geometric Effects of La_(1+x)Mg_(2-x)Ni_9 (x=0.0~1.0) Ternary Alloys on Their Hydrogen Storage Capacities

Structural analysis was made using X-ray diffraction (XRD) Rietveld refinement on a series of La1+xMg2-xNi9 (x=0.0-1.0) ternary alloys. Results showed that each of La1+xMg2-xNi9 alloys was a PuNi3-type structure stacked by LaNi5 and (La, Mg) Ni2 blocks. Electrochemical tests revealed that discharge abilities of these La-Mg-Ni ternary alloys mainly depended on their atomic distances between (La, Mg) and Ni, which could be modified by varying the atomic ratios of La/Mg.

PREDICTION ON THERMODYNAMIC PROPERTIES OF TERNARY LIQUID ALLOYS FROM WILSON EQUATION

An attempt was made on applying the Wilson equation to predict the thermodynamic proper- ties of ternary liquid alloys.The activity of each component in ternary liquid alloys was found to be conveniently calculated from the equation with the related binary bimolecular interaction parameters.The calculated values are in fair agreement with experimental data,and are veri- fied to be reliable by the criterion of classical thermodynamics.

Relations between compositional modulation and atomic ordering degree in thin films of ternary Ⅲ-Ⅴ semiconductor alloys

This paper derives the expressions for the ordering degree and the modulation factor of A and B atoms in AXB1-xC epilayers of ternary III-V semiconductor alloys. Using these expressions, it identifies quantitatively the alternating atom-enhanced planes, compositional modulations, atomic ordering degree on the group-III sublattices and the fine structure of NMR spectra.

Miscibility Calculation of GaN1-xPx Ternary Alloys

A theoretical calculation of the miscibility gap with considering the mismatch strain and elastic parameters was performed for the GaN1-xPx ternary alloys on (0001) GaN/sapphire substrates based on the strictly regular solution model. The calculated results show that the boundary of the spinodal isotherm shifts from x=0.06 to x=0.25 at the growth temperature of 1200 K as the strain factor increases from 0 to 1, indicating that the strain in the GaN1-xPx layers can suppress the phase separation. Meanwhile, with the increase of the effective elastic parameters of GaN and GaP, the available maximum P content also increases slightly at the growing temperature.

Stoichiometric NbTiAl_3 (γ1 Phase) Alloy in Ti-Al-Nb Ternary System

The microstructure and phase constitution in stoichiometric NbTiAl3 (γ1 phase) alloy treated at 1000℃ were examined by metallography and X-ray diffraction. The alloy microstructure is mainly γ1 phase containing η second phase [(Ti,Nb)Al3] less than 1%. DTA analysis shows no phase transformation from room temperature to 1200℃. In the diffusion couple of NbTiAl3 with 7-TiAl compound, clear phase boundary and composition jump exist between γ1 and γ phase.These results further confirm the existence of γ1 single phase at 1000℃ in Ti-Al-Nb ternary system.

The Bowing Parameters of Ca_χMg_1-χO Ternary Alloys

On the basis of first principles calculations using density functional theory, we explore the structural and electronic properties of two binaries: CaO and MgO in rock salt structures. Structural properties of the semiconductor CaχMg1-χO alloys are derived from total-energy minimization within the General Gradient Approximation. The band gap bowing parameters dependence is very powerful Calcium composition. The results offer that an average bowing parameter of CaχMg1-χO alloys is b = ~0.583$ eV. We analyzed the volume deformation, charge transfer and structural relaxation effects of the CaχMg1-χO alloys.

Corrosion behavior of ternary Fe-15Cu-5Al alloy in pure oxygen at 1 000 ℃

The corrosion behavior of ternary Fe-15Cu-5Al(mole fraction,%) alloy was studied at 1 000 ℃ in 0.1 MPa pure oxygen. The Fe-rich alloy shows two parabolic oxidation stages,with a small increase of the parabolic rate constant from 1.9×10-9 to 4.1×10-9 g2/(cm4·s). The scale grown on the alloy is very complicated,with formation of overgrown nodules interspersed among bulky stratified scales. The nodules and the bulky stratified scales are always composed of an outer layer of CuFe2O4 and of an inner layer containing Fe2O3 and Fe3O4. Beneath the external scale of the nodules,there is an internal oxidation zone where iron oxide is mixed with copper metal. Furthermore,the base of the internal oxidation zone is characterized by a discontinuous aluminum-enriched layer of either Al2O3 or FeAl2O4. For the stratified scales,no internal oxidation zone is present beneath the innermost Al2O3 or FeAl2O4 layer. Aluminum depletion is present in advance of the internal oxidation front,while iron depletion is not observed. The corrosion feature of the ternary Fe-15Cu-5Al alloy is partly associated with that of the corresponding binary Fe-Cu and Fe-Al alloys. The peculiar scale microstructure observed is considered mainly as a consequence of the limited solubility of the iron and copper components in one another and of the monovariant system of the ternary Fe-15Cu-5Al alloy.

Complete Maps for the Internal Oxidation of Ideal Ternary Alloys Forming Insoluble Oxides under High Oxidant Pressures

This paper presents an analysis of the conditions of stability of the different forms of internal oxidation of ideal ternary A-B-C alloys,where A is the most noble and C the most reactive component, forming insoluble oxide and exposed to high pressures of a single oxidant.The treatment,based on an extension to ternary alloys of Wagner' s criterion for the transition from internal to external oxidation in binary alloys,allows to predict the existence of three different forms of internal oxidation.In fact,in addition to the most common kinds of internal attack,involving the coupled internal oxidation of B+C beneath external AO scales and the internal oxidation of C beneath external BO scales,a third mode, involving the internal oxidation of C beneath external scales composed of mixtures of AO+BO,becomes also possible under special conditions.A combination of the boundary conditions for the existence of these different types of internal oxidation allows to predict three different kinds of complete maps for the internal oxidation in these systems,one of which involves only two modes,while the other two involve all the three possible modes of internal oxidation.