Dissolution Of Sn Research Articles

Microstructure characterization and age hardening response of Mg-8Sn-2Al alloy with Bi, Ag addition

The effects of Bi and Ag addition on the microstructure and age hardening response of Mg-8Sn-2Al alloy were investigated in this study. The Mg2Sn phase distributed along grain boundaries was observed in as-cast Mg-8Sn-2Al alloys and disappeared after solution treatment due to the Sn dissolution into ɑ-Mg matrix. However, a majority of Mg2Sn phase disappeared and few Mg2Sn particles still existed in the solid solutioned Mg-8Sn-2Al alloys containing Bi element. Mg2Sn precipitates formed in all peak-aged alloys. And Al, Bi and Ag elements are enriched in the areas of lath-shaped and spherical Mg2Sn precipitates in peak-aged Mg-8Sn-2Al-1.5Bi-1Ag alloy. Bi and Ag elements can act as heterogeneous nucleation sites and restrict the growth of precipitates to improve the age hardening response of Mg-8Sn-2Al alloy. Meanwhile, the undissolved Mg3Bi2 phase or early precipitated Mg3Bi2 phase during ageing treatment probably change the morphology and elements distribution of Mg2Sn precipitates. In addition, Ag and Bi atoms play a role on grain refinement and solution strengthening in Mg-8Sn-2Al alloy. Therefore, the micro-hardness value of peak-aged Mg-8Sn-2Al-1.5Bi-1Ag alloy increased to 69.9 HV from 47.4 HV of solid solutioned Mg-8Sn-2Al alloy. The precipitation behaviour, refined second phase, grain refinement and solute atoms synergistically made contributions to the strength improvement. The roles of Bi and Ag elements on improving age hardening response and precipitates characteristics are discussed in this study, which provides an important reference for exploring aged Mg-Sn alloys.

Comparison of Electrochemically Deposited Bi and Sn Catalysts onto Gas Diffusion Electrodes for the Electrochemical CO2 Reduction Reaction to Formate

In this publication, we report about the selectivity and stability of bismuth (Bi)- and tin (Sn)-based electrocatalysts for the electrochemical CO2 reduction reaction (eCO2RR) for formate production. Bismuth and tin were successfully electrodeposited using the pulse plating technique on top of and inside of the gas diffusion layers (GDLs). The distribution of the catalyst throughout the thickness of the gas diffusion electrodes (GDEs) was investigated by using scanning electron microscopy and computer tomography; it was found that the catalyst morphology determines the performance of the electrode. Inhomogeneous deposits, with their enlarged catalyst surface area, provide more active centres for the eCO2RR, resulting in increased Faraday efficiency (FE) for formate. The initial electrochemical characterisation tests of the bismuth- and tin-loaded GDEs were carried out under laboratory operating conditions at an industrially relevant current density of 200 mA·cm−2; complete Sn dissolution with a subsequent deformation of the GDL was observed. In contrast to these results, no leaching of the electrodeposited Bi catalyst was observed. An FE of 94.2% towards formate was achieved on these electrodes. Electrodes based on an electrodeposited Bi catalyst on an in-house prepared GDL are stable after 23 h time-on-stream at 200 mA·cm−2 and have very good selectivity for formate.

Characterization of structure and hardness at aging of the A319 type aluminum alloy with Sn trace addition

The effect of 0.1 wt% (0.02 at%) Sn trace addition on the structure and phase composition of Al-Si-Cu based alloy has been studied using thermodynamic calculations (Thermo-Calc software) and experimental techniques (transmission electron microscopy (TEM), atom probe tomography (APT), hardness and specific electrical conductivity measurements). The Vickers hardness measurement made after aging at 175 °C revealed that the peak hardness of the Sn-containing alloy is about 22% higher than that of the Sn-free alloy (135 HV vs 115 HV). Moreover, the peak hardness is achieved in a much shorter aging time (4 h vs 16 h). Considerably finer precipitates of the θ′ phase (average length less than 60 nm and thickness 3–5 nm) with a substantially higher number density are observed in the Sn-containing alloy. Tiny, rounded particles most of which are associated with the θ′ phase precipitates are also observed. Atom probe tomography analysis confirmed that the observed nanoparticles consist of tin. Quantitative APT analysis revealed that the number density of the copper-containing precipitates is at least twice that of the tin-containing ones (7.6·104 vs 3·104 µm-3). APT data also revealed a clear evidence of noticeable dissolution of Sn (average concentration from 0.05 to 0.10 at%) and silicon (average concentration from 2.2 to 2.8 at%) at the core of the θ′ phase precipitates, which is consistent with the fact that Sn and to a lesser extent Si act as catalysts in the nucleation of this phase. The data obtained using the proxigram technique suggest that Sn atoms show no tendency to segregate at the coherent θ′/(Al) heterophase interface upon aging, whereas localized Sn segregation is observed at the semi-coherent interface. Both Sn-free and Sn-containing alloys in their peak aged states have been subjected to uniaxial compression tests at an elevated temperature of 250 °С. The results suggest that the yield strength of the Sn-containing alloy is about 1.5 times that of the Sn-free alloy (250 MPa vs 175 MPa). The revealed difference is very big and testifies to a high potential of the new alloys as materials for new-generation engine parts.

Electrochemical dissolution and recovery of tin from printed circuit board in methane–sulfonic acid solution

Current industrial Sn stripping processes from raw printed circuit board (PCB) are carried out typically in nitrate system and inevitably produce low-concentration NOX gas pollutant and high-concentration nitrate wastewater. This study proposes a novel and high-efficient Sn electrochemical stripping and recovery method from PCBs in methane–sulfonic acid (MSA) solution. A PCB covered with Sn was used as the anode, and Sn was removed by one-step method and deposited on the cathode in the electrolysis process. This work also investigated the influences of various electrolysis conditions on the change of current efficiency, electric power consumption, and PCB surface morphology. The optimal conditions were 40 °C, 60 g/L Sn2+, 100 g/L MSA, 60 mm inter-electrode spacing, and 200 A/m2 current density for Sn dissolution and extraction. About 85% of Sn was removed from the anodic PCB and subsequently electrodeposited at the cathode under the most suitable conditions. The electric power consumption was 63 kWh/t-Sn, and the electrolyte had a long lifetime. Moreover, the copper layer was not corroded, and no Sn remained on the surface of the anodic PCB after immersion in the picking solution. This novel technique provides an efficient alternative for Sn removal and recovery from PCB and will promote resource recycling and environment protection in raw PCB manufacturing industry.

In-situ study of electrochemical migration of tin in the presence of bromide ion

The miniaturization of electronic devices and the consequent decrease in the distance between conductive lines have increased the risk of short circuit failure due to electrochemical migration (ECM). The presence of ionic contaminants affects the ECM process. This work systematically investigates the ECM of tin (Sn) in the presence of bromide ions (Br−) in the range of 10−6 M to 1.0 M. Water drop test (WDT) was conducted in the two-probe semiconductor characterization system under an optical microscope as an in-situ observation. Polarization test was carried out to study the correlation between the corrosion properties of Sn and its ECM behaviour. The products of ECM were characterized by scanning electron microscope coupled with an energy dispersive X-rays spectrometer (SEM/EDX) and X-ray photoelectron spectrometer (XPS). The results confirm that the rate of anodic dissolution of Sn monotonously increases with the Br− concentration. However, the probability of ECM failure follows a normal distribution initially, but later increases with the Br− concentration. The main products of the ECM reactions are identified as Sn dendrites and tin hydroxide precipitates. The mechanisms of the ECM process of Sn in the presence of Br− are also suggested.

Dissolution Behavior of Sn in CaO–CaF2 Molten Flux and Its Distribution Ratio Between CaO–CaF2 Molten Flux and Liquid Iron

The dissolution behavior of Sn in CaO– $$\hbox {CaF}_2$$ flux was investigated. A chemical equilibration technique was employed which allows pure liquid Sn dissolves into the molten flux under various oxygen partial pressure and the flux composition. At an equilibrium, (% Sn) in the flux increased by increasing (% CaO) and $$p_{\text{O}_2}$$ . It was found that Sn dissolves into the molten flux as ( $$\hbox {SnO}_3$$ ) $$^{4-}$$ in the condition of the present study. Distribution of Sn between CaO saturated flux and C saturated liquid Fe was measured under a pure CO atmosphere. Sn distribution ratio ( $$L_{\text{Sn}} = (\%\,\text{Sn})_{\text{flux}}/[\%\,\text{Sn}]_{\text{iron}}$$ ) was as low as $$\sim 10^{-4}$$ , which was consistent with a thermodynamic prediction. Sn distribution was favored at a lower temperature. Thermodynamic modeling was carried out for the Sn dissolution in the flux. A noticeable negative deviation between CaO and SnO was identified.

Oxygen Evolution Reaction on Tin Oxides Supported Iridium Catalysts: Do We Need Dopants?

AbstractApplication of oxide supports is considered as a viable approach to decrease iridium loading in oxygen evolution reaction catalysis in acid electrolyte. While the most of the promising oxides are poor conductors, the need for doping is typically taken as granted, and a representative example is tin dioxide. There are still, however, serious concerns on the feasibility of this approach as we lack consensus on any activity gain by using such oxides, while doubts on stability are numerous. In this work, a set of catalyst/support combinations including two catalysts, viz. hydrous (IrOx) and rutile (IrO2) iridium oxides, and four supports, viz. SnO2 and Sb‐ (ATO), F‐ (FTO), and In‐doped (ITO) SnO2, are synthesized and characterized by a selection of complementary experimental techniques including rotating disk electrode and on‐line inductively coupled plasma mass spectrometry. It is found that the electrochemical activity in acid media of supported Ir catalysts is essentially the same, independent on presence or absence of dopants. Sb and In dopants are shown to be unstable and cause an increased dissolution of Sn. Besides, the degradation of the doped supports results in destabilization of iridium oxides. These results raise doubts on the real need for the use of dopants in SnO2‐based catalyst supports for electrochemical water splitting.

Structural and electrochemical properties of (SnxCo100-x)50C50 anodes for Li-ion batteries

Phase formation and electrochemical characteristics of (SnxCo100-x)50C50 (x = 34, 71, 85 wt %) composite anodes prepared by ball milling of melt spun alloys and graphite powder is studied for Li-ion battery applications. The maximum specific capacity of these anodes is 260 mAh g−1 for the Co rich alloy, 400 mAh g−1 for the equi-atomic alloy and a fading capacity of 335 mAh g−1 to 205 mAh g−1 in Sn rich alloy. Anodes made of Co rich and equi-atomic composition deliver stable capacity of 74% of the theoretical value due to the presence of nanocrystalline Sn–Co compounds. Sn rich composition exhibits a large fading in capacity below 55% of the theoretical value, due to the presence of soft Sn phase. The formation of nanocrystalline structure by ball milling is prevented in the Sn rich alloy due to the presence of this soft phase. A highly non uniform porous structure is formed during cycling of the Sn rich anodes, causing poor reversibility. Ball milling leads to the dissolution of Sn–Co compounds in the matrix phase, whereas the softer Sn and C elements do not dissolve. The structure of Sn–Co phase is further completely lost by charge-discharge cycling, forming non-crystalline Li–Sn phase in all the alloys. The equi-atomic Sn–Co composition is shown to be most suitable for making SnCoC anode compared to the Sn rich or Co rich compositions.

Evaluation of silver -copper-tin brazing alloy corrosion behavior in chloride containing electrolyte at various temperature

Silver base brazing alloys are commonly used for brazing most of ferrous and nonferrous metals alloys. These families of filler metals have a lower brazing temperature due to Sn addition thus offers excellent flow. Meanwhile, the high content of Ag in the alloys guarantees a good corrosion resistance. However, the detrimental effect was shown when it joints in stainless steel. In present work, corrosion behavior of silver-copper-tin brazing alloy was evaluated. The brazing alloy was exposed to water contained chloride and the temperatures were varied at 25, 40, 55, and 70 °C. The electrochemical methods were utilized to evaluate the corrosion behavior of the alloy. The results showed that the dissolution of Sn seems to be initiating the corrosion of the silver-copper-tin brazing alloy. Nevertheless, the active dissolution of the Cu to the solution simultaneously influence the corrosion behavior of the silver-copper-tin brazing alloy. This study in terms of the alloy corrosion behavior in the particular environment should give both of academicals and industrials contributions.

Corrosion behavior of Sn-3.0Ag-0.5Cu lead-free solder joints

The aim of this study is to evaluate the corrosion behavior of Sn-3.0Ag-0.5Cu (SAC305) lead-free solder joint using salt spray test. The presence of Cu pad accelerates the dissolution of Sn from solder joints into corrosive medium because of galvanic corrosion mechanism. So, the solder joint was easily corroded in corrosive environment than SAC305 solder bar. During salt spray test, pitting corrosion begin from the solidification cracks in the solder joints, which will lead to a decrease of the reliability of solder joints and shorten the life of electronic devices.

The function of Sn(II)-apatite as a Tc immobilizing agent

At the U.S. Department of Energy Hanford Site, Tc-99 is a component of low-activity waste (LAW) fractions of the nuclear tank waste and removal of Tc from LAW streams would greatly benefit the site remediation process. In this study, we investigated the removal of Tc(VII), as pertechnetate, from deionized water (DIW) and a LAW simulant through batch sorption testing and solid phase characterization using tin (II) apatite (Sn-A) and SnCl2. Sn-A showed higher levels of Tc removal from both DIW and LAW simulant. Scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/XEDS) and X-ray absorption spectroscopy (XAS) of reacted Sn-A in DIW showed that TcO4- is reduced to Tc(IV) on the Sn-A surface. The performance of Sn-A in the LAW simulant was lowered due to a combined effect of the high alkalinity, which lead to an increased dissolution of Sn from the Sn-A, and a preference for the reduction of Cr(VI).

Non-equilibrium induction of tin in germanium: towards direct bandgap Ge(1-x)Sn(x) nanowires.

The development of non-equilibrium group IV nanoscale alloys is critical to achieving new functionalities, such as the formation of a direct bandgap in a conventional indirect bandgap elemental semiconductor. Here, we describe the fabrication of uniform diameter, direct bandgap Ge1−xSnx alloy nanowires, with a Sn incorporation up to 9.2 at.%, far in excess of the equilibrium solubility of Sn in bulk Ge, through a conventional catalytic bottom-up growth paradigm using noble metal and metal alloy catalysts. Metal alloy catalysts permitted a greater inclusion of Sn in Ge nanowires compared with conventional Au catalysts, when used during vapour–liquid–solid growth. The addition of an annealing step close to the Ge-Sn eutectic temperature (230 °C) during cool-down, further facilitated the excessive dissolution of Sn in the nanowires. Sn was distributed throughout the Ge nanowire lattice with no metallic Sn segregation or precipitation at the surface or within the bulk of the nanowires. The non-equilibrium incorporation of Sn into the Ge nanowires can be understood in terms of a kinetic trapping model for impurity incorporation at the triple-phase boundary during growth.

Thermal Treatment of MgO-Protected Ptsn/C Catalyst: Stability and Ethanol Oxidation

The direct ethanol fuel cell (DEFC) is an alternative solution to energy-generation problems. However, the ethanol oxidation kinetics is slow and inefficient, due to the difficult to break C–C bond at practical potentials. Furthermore, catalysts instability is a problem and it is associated with the dissolution of non-noble metal and the nanoparticles agglomeration. Therefore, the studies of stability and influence of physical and chemical properties in catalytic activity of materials are very important to the development of efficient catalysts. Even the most thoroughly studied PtSn catalyst continue to lack understanding and it is need more fundamental research to improve the performance of PtSn catalyst in fuel cell. Herein, we present a comparative study of physical and electronic properties and catalytic activities for ethanol oxidation of carbon-supported binary (PtSn) metallic nanoparticles. The PtSn-based catalysts were synthesized and coated with MgO by a polyol method. Subsequently, nanoparticles were supported on carbon powder (Vulcan XC-72) and divided into two parts. Each part was treated at 500ºC for 1 hour with different atmospheres (Hydrogen and Argon). After thermal treatment, the MgO were removed with H2SO4 solution. The materials were metal load of 20% wt, (metal = Pt, Sn). The catalysts were characterized by X-ray diffraction (XRD), transmission electronic microscopy (TEM) and EDX. Their catalytic activities for ethanol oxidation reaction were studied and the performance of stability test was evaluated by potential sweeps. It was observed XRD patterns with typical peaks of face-centered cubic structure of Pt and the catalysts showed different fases and alloy amount. The atomic composition PtSn was about 60:40. TEM analysis showed particles homogenously dispersed in carbon support and indicated average particle sizes of 3,9 and 2,9 nm for Hydrogen and Argon, respectively. The MgO coatings were effective as the particles do not accret during thermal treatment, according to DRX and TEM analyses. The voltammetry profile and value of currents were similar for all samples. Catalysts showed better performance than PtSn ETEK for CO adsorved oxidation after and before stability test. It was observed an increasing on current density in H adsorption/desorption region after stability test. It is known that CO electro-oxidation reaction on Pt is structure-sensitive and considering the sweep linear profile of oxidation CO difference, it is possible to see a change in surface structure of Sn-based catalysts after stability test. Possibly the change of surface structure is due to Sn dissolution during voltammetry cyclic sweeping and/our coalescence of nanoparticles. It was confirmed by highest on set potential of CO oxidation and decrease current density of ethanol oxidation after stability test. Two important points are evident: first, activity for CO oxidation improved with less Sn in the alloy. Second, the stability decrease can be influenced by the higher amount of Sn in the alloy. In conclusion, this study showed the catalysts with more Sn oxide had better stability and the PtSn/C catalyst treated in Hydrogen was the most active for ethanol oxidation. The sample treated in Argon was more effective for CO oxidation, evidencing that the surface processes involved in the bifunctional mechanism are relevant to the oxidation of CO.

Dissolution of Sn, SnO, and SnS in a Thiol-Amine Solvent Mixture: Insights into the Identity of the Molecular Solutes for Solution-Processed SnS.

Binary solvent mixtures of alkanethiols and 1,2-ethylenediamine have the ability to readily dissolve metals, metal chalcogenides, and metal oxides under ambient conditions to enable the facile solution processing of semiconductor inks; however, there is little information regarding the chemical identity of the resulting solutes. Herein, we examine the molecular solute formed after dissolution of Sn, SnO, and SnS in a binary solvent mixture comprised of 1,2-ethanedithiol (EDT) and 1,2-ethylenediamine (en). Using a combination of solution (119)Sn NMR and Raman spectroscopies, bis(1,2-ethanedithiolate)tin(II) was identified as the likely molecular solute present after the dissolution of Sn, SnO, and SnS in EDT-en, despite the different bulk material compositions and oxidation states (Sn(0) and Sn(2+)). All three semiconductor inks can be converted to phase-pure, orthorhombic SnS after a mild annealing step (∼350 °C). This highlights the ability of the EDT-en solvent mixture to dissolve and convert a variety of low-cost precursors to SnS semiconductor material.

Electrochemical behaviour of tin in alkaline electrolyte

The electrochemical behaviour of two types of tin electrodes, Sn rod and electrodeposited Sn is investigated in 0.1M KOHaq in order to evaluate processes related to anodic Sn dissolution. Potential regions of formation of soluble Sn(II) and Sn(IV) are identified by means of a rotating ring disk electrode. An anodic reactivation peak observed for cathodic potential scans for partially passivated electrodes is accompanied by formation of soluble Sn(II) species and a minimum in the imaginary part of the impedance. This confirms that the reactivation peak is due to active dissolution of metallic Sn exposed to the electrolyte during rupture of the oxidised layer.

Electro-oxidation of ethanol on ternary non-alloyed Pt–Sn–Pr/C catalysts

Ternary Pt–Sn–Pr/C (70:10:20), (70:15:15) and (45:45:10) electro-catalysts were prepared by a modified formic acid method, and their activity for the ethanol oxidation reaction (EOR) was compared with that of Pt–Pr/C catalysts prepared by the same methods and that of commercial Pt–Sn/C (75:25) and Pt/C catalysts. Among all the catalysts, the Pt–Sn–Pr/C (45:45:10) catalyst presented both the highest mass activity and the highest specific activity. The steady state electrochemical stability of ternary Pt–Sn–Pr catalysts increased with the surface Sn/Pt atomic ratio. Following repetitive potential cycling (RPC), the activity for ethanol oxidation of Pt–Sn–Pr/C catalysts with high surface Sn/Pt atomic ratio was considerably higher than that of the corresponding as-prepared catalysts, and increased with increasing the Sn/Pt ratio. The increase of the EOR mass activity following RPC was ascribed to the increase of either the specific activity (for the Pt–Sn–Pr/C (70:15:15) catalyst) or the electrochemically active surface area (for the Pt–Sn–Pr/C (45:45:10) catalyst). Dissolution of Sn and Pr oxides from Pt–Sn–Pr/C catalyst surface was observed following RPC.

Separation of Tin, Silver and Copper from Waste Pb-free Solder Using Hydrochloric Acid Leaching with Hydrogen Peroxide

The waste lead (Pb)-free solder leaching process in hydrochloric acid (HCl) solution with hydrogen peroxide (H2O2) followed by separation of copper (Cu) and tin (Sn) was investigated to separate tin, silver (Ag), and copper as an individual component from waste Pb-free solder. The dissolution of Sn increased with increasing temperature and HCl concentration. The concentrations of Sn and Cu increased to 27090g·m ¹3 and 191g·m ¹3 , respectively, under the leaching condition with 1kmol·m ¹3 HCl, 0.8kmol·m ¹3 H2O2 at 50°C and 400rpm for 120min, while Ag is not detected in all leaching tests. The Sn and Cu components are thus successfully separated from Ag by hydrochloric acid leaching with hydrogen peroxide. To precipitate selectively Cu ions from the leach solution, the method to add Sn powder has been investigated. Thus, 92.8g·m ¹3 (1.46mol·m ¹3 ) of Cu could be removed successfully from the leach solution with Sn under the following conditions; 30°C in temperature; 400rpm in agitation speed; 0.3mlmin ¹1 in N2 flow rate; 0.1g Sn powder addition to 100cm 3 leach solution.

Characterization of Pt catalysts on Nb-doped and Sb-doped SnO2–δ support materials with aggregated structure by rotating disk electrode and fuel cell measurements

We found high activity and durability for oxide-supported Pt catalysts for the oxygen reduction reaction (ORR). These catalysts were supported on Sn0.96Nb0.04O2–δ (Pt/Sn0.96Nb0.04O2–δ; BET area of support, 37m2g−1; Pt loading, 10.0wt%) and Sn0.96Sb0.04O2–δ (Pt/Sn0.96Sb0.04O2–δ; BET area of support, 33m2g−1; Pt loading, 12.3wt%), by use of the rotating disk electrode (RDE) technique, and measured the I–E performance of single H2-air polymer electrolyte fuel cells (PEFCs) using these catalysts as the cathode. The nanoparticulate supports Sn0.96Nb0.04O2–δ and Sn0.96Sb0.04O2–δ had an aggregated structure similar to that of carbon black (CB). The electrochemically active surface area of Pt, estimated by cyclic voltammetry measurements with the RDE, reached 79.7m2g−1 (Pt/Sn0.96Nb0.04O2–δ) and 68.6 m2g−1 (Pt/Sn0.96Sb0.04O2–δ). The ORR activity of Pt/Sn0.96Nb0.04O2–δ exceeded that of a commercialized Pt catalyst supported carbon black (Pt/CB). Higher durability was confirmed for Pt/Sn0.96Nb0.04O2–δ and Pt/Sn0.96Sb0.04O2–δ compared to that of Pt/CB with a test protocol for start/stop cycling recommended by the Fuel Cell Commercialization Conference of Japan (FCCJ) [1]. Single cells using these catalysts showed I–E performance superior to that for the Pt/CB at operating potentials above 0.4V. For operating potentials below 0.4V, a slight amount of Sn dissolution from the Sn0.96Sb0.04O2–δ support occurred, resulting in degradation of the cell performance due to Pt poisoning by Sn re-deposition, but no noticeable degradation at Sn0.96Nb0.04O2–δ was found, due to the suppressed Sn dissolution.

High activity of carbon nanotubes supported binary and ternary Pd-based catalysts for methanol, ethanol and formic acid electro-oxidation

In this study, we have synthesized a series of multi-walled carbon nanotubes supported Pd, PdCu(molar ratio 1:1), PdSn(1:1) and PdCuSn(1:1:1) catalysts by chemical reduction with NaBH4 as a reducing agent. These catalysts are characterized using X-ray diffraction, transmission electron microscopy, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy (XPS), cyclic voltammetry and chronoamperometry. During the potential cycling activation, it is found that the additive Cu is prone to suffer leaching while the dissolution of Sn rarely occurs. Electrochemical measurements demonstrate that, the co-alloying of Pd with Cu and Sn can trigger the best catalytic activity enhancement as compared with the binary PdCu/CNTs, PdSn/CNTs and mono-component Pd/CNTs catalysts. The PdCuSn/CNTs reveals the most excellent activities toward methanol, ethanol and formic acid electro-oxidation and the corresponding mass activity can attain to 395.94, 872.70 and 534.83 mA mg−1 Pd, respectively. The possible promotion effect of additive Sn or/and Cu on the electrocatalytic activity improvement is also analyzed.

Mechanically Driven Dissolution of Sn in Near-Equiatomic Bcc FeCo

Ternary alloys, (Fe50−x/2Co50−x/2)Snx(x ≤ 33 at.%), are prepared by mechanical alloying from powder mixtures of the three elements. As-milled alloys are studied by X-ray diffraction and 57Fe and 119Sn Mössbauer spectroscopy. The solubility of Sn in near-equiatomic bcc FeCo is increased from ~0.5 at. % at equilibrium to ~20 at.% in the used milling conditions. The average 119Sn hyperfine magnetic field at room temperature is larger, for any x, than the corresponding fields in mechanically alloyed Fe-Sn solid solutions.