Metal alloy activation

In liquid metal solutions Z is normally of the order of 10, and so this equation gives values of Ks(a+B) which are close to that predicted by the random solution equation. But if it is assumed that the solute atom, for example oxygen, has a significantly lower co-ordination number of metallic atoms than is found in the bulk of die alloy, dieii Z in the ratio of the activity coefficients of die solutes in the quasi-chemical equation above must be correspondingly decreased to the appropriate value. For example, Jacobs and Alcock (1972) showed that much of the experimental data for oxygen solutions in biiiaty liquid metal alloys could be accounted for by the assumption that die oxygen atom is four co-ordinated in diese solutions. 

The NO reduction over Cu-Ni-Fe alloys has been studied recently by Lamb and Tollefson. They tested copper wires, stainless steel turnings, and metal alloys from 378 to 500°C, at space velocities of 42,000-54,000 hr-1. The kinetics is found to be first order with respect to hydrogen between 400 and 55,000 ppm, and zero order with respect to NO between 600 and 6800 ppm 104). The activation energies of these reactions are found to be 12.0-18.2 kcal/mole. Hydrogen will reduce both oxygen and NO when they are simultaneously present. CO reduction kinetics were also studied over monel metals by Lunt et al. 43) and by Fedor et al. 105). Lunt speculated that the mechanism begins by oxidant attack on the metal surface... 

Superconductivity has been known since 1911, and superconducting systems based on various metal alloys (e.g., NbTi and Nb3Sn) are currently used as magnets and in electronics. These materials exhibit superconductivity only at temperatures below 23 K and require cooling by liquid helium. The discovery of ceramics that exhibit superconductivity at temperatures up to 120 K, the so-called high-temperature superconductors, has sparked a tremendous amount of scientific activity and commercial interest around the world. 

The search for new, more highly active and less expensive materials for catalytic electrodes and the attempts at reducing the loading of expensive platinum catalysts has led to numerous studies in the area of binary and multicomponent metal systems. These included various metal alloys as well as mixed microdeposits containing several... 

The above results demonstrate that computational screening is promising technique for use in electrocatalyst searches. The screening procedure can be viewed as a general, systematic, DFT-based method of incorporating both activity and stability criteria into the search for new metal alloy electrocatalysts. By suggesting plausible candidates for further experimental study, the method can, ultimately, result in faster and less expensive discovery of new catalysts for electrochemical processes. 

Runnalls, O. J. C. Alloying Active Metals with Aluminium or Beryllium. 

An overview about more than 10 years of R D activities on solid electrolyte interphase (SEI) film forming electrolyte additives and solvents at Graz University of Technology is presented. The different requirements on the electrolyte and on the SEI formation process in the presence of various anode materials (metallic lithium, graphitic carbons, and lithium storage metals/alloys are particularly highlighted. 

The capabilities of thin tin films and tin-based alloys with different metals as active materials for lithium - ion battery negative electrodes are considered. Electrochemical characteristics of such films at different substrates and mechanisms of their functioning are discussed. 

The metal ion in electroless solutions may be significantly complexed as discussed earlier. Not all of the metal ion species in solution will be active for electroless deposition, possibly only the uncomplexed, or aquo-ions hexaquo in the case of Ni2+, and perhaps the ML or M2L2 type complexes. Hence, the concentration of active metal ions may be much less than the overall concentration of metal ions. This raises the possibility that diffusion of metal ions active for the reduction reaction could be a significant factor in the electroless reaction in cases where the patterned elements undergoing deposition are smaller than the linear, or planar, diffusion layer thickness of these ions. In such instances, due to nonlinear diffusion, there is more efficient mass transport of metal ion to the smaller features than to large area (relative to the diffusion layer thickness) features. Thus, neglecting for the moment the opposite effects of additives and dissolved 02, the deposit thickness will tend to be greater on the smaller features, and deposit composition may be nonuniform in the case of alloy deposition. 

For example, consider the bi-metallic alloy known as bronze, which contains tin (30 mol%) and copper (70 mol%). There are two activities in this alloy system, one each for tin and copper. The activity of each metal is obtained as its respective mole fraction x,... 

Alkaline glycerol electrochemical oxidation on Pt-Pd alloys is dependant on the surface composition of the alloys. Compared with the pure metals, enhanced activity is found when the alloy contains about 33% Pd, leading to a synergetic effect [63]. 

Several lanthanide-transition metal alloys (LaNi5, PrCo5, SmCo5) readily absorb large volumes of hydrogen under mild conditions, and some of these alloy hydrides function as active hydrogenation catalysts e.g., the title structures, which are pyrophoric in air. Analogous hydrides may be expected to behave similarly. 

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