LaNis

FeTi can also be modified with rare-earth metals, Ni, or Mn (15). AB alloys where A is a rare-earth metal or mischmetal, Ca, or Th, and B is Co or Ni have also been used. LaNi has shown special promise (16). 

Storage as Hydrides. The discovery of metal compounds that reversibly absorb hydrogen is relatively recent. In the 1970s, the AB and AB family of alloys, which reversibly absorb hydrogen at room temperature and low pressure, were identified (205). Both A and B are metals. As of this writing many such compounds are known LaNi and TiFe are examples. 

The lanthanides can form hydrides (qv) of any composition up to LnH. Lanthanide hydrides can desorb hydrogen reversibly with temperature. Therefore, the lanthanides and some of thek alloys ate good candidates for hydrogen (qv) storage, of which LaNi is probably the most promising (see... 

Fig. 20. Pressure concentration curves of MmNi (—) and LaNi (— ) at 45°C where open circles denote absorption and closed circles desorption of hydrogen. H/M represents the ratio in the hydride of the mole fraction of hydrogen to the mole fraction of the metal.

WENZEL - IMAMOTO Reduction Selective reductions ol C>C with LaNI alloy... 

General procedure. LaNIs ingot (3 g) in an autoclave was evacuated at 0.1 mm, heated to 200°C under Hz at 30 atm for 10 min. After cooling to 20°C, Itie operation was repeated five times. The autoclave was cooled in dry ice-acetone, Hg was released and Ng was Introduced. The organic compound (1 mmol) m THFJ4eOH (2 1) (5 mL) was added at -78°C with stirring. Tt mixture was stirred under Ng at 0°C and then at 20°C. The catalyst was filtered, the filtrate concentrated and the residue purified by preparative TLC on silica gel. 

Freight Movement John Zumerchik Jack Lani an, Sr. 

Hydrogen absorbing alloy LaNis, LaNi4Co, LaNi3C02, LaNi2C03, Lao8Ceo.2Ni2C03,... 

LaNis has the CaCu, structure, space group P6/mmm [26] the hexagonal metal lattice is shown in Fig. 4. The crystal structure of LaNi5D7 has been determined 127, 28] and is illustrated in Fig. 5. There are three types of interstitial D sites La2Ni4 tetrahedra, and NiA tetrahedra. The unit cell is doubled along the oaxis because of the formation of a superlattice which is a consequence of long-range correlations between occupied and unoccupied... 

With reference to rule (3) (Sec. 7.1.3) regarding metal atom mobility, we note that the Gibbs free energies of formation (AG( ) at 298 K for LaNi s and for LaH2 are about -67 and -171 kJ mol-1 respectively. Thus the following disproportionation reaction is highly favored [29] ... 

Figure 6. Schematic representation of the reaction paths for hydriding and dehydriding LaNis [331.

Cobalt is invariably present in commercial MHt battery electrodes. It tends to increase hydride thermodynamic stability and inhibit corrosion. However, it is also expensive and substantially increases battery costs thus, the substitution of Co by a lower/cost metal is desirable. Willems and Buschow [40] attributed reduced corrosion in LaNi 5 vCoi (x= 1 -5) to low Vn. Sakai et al. [47 J noted that LaNi25Co25 was the most durable of a number of substituted LaNi5 iCoi alloys but it also had the lowest storage capacity. 

Manganese is also present in most commercial electrodes. In a series of experiments examining the cycle lives of the homologous alloys LaNi M (M= Mn, Cu, Al, and Co) Sakai et al. [50] noted that Mn was the least effective. In more complex alloys examined by Adzic et al. 

Figure 16. AV/V (%), wt.% corroded/cycle, and H content vs. Al content, x, in LaNi 1K5 xCoa7,Mn(uAlx electrodes [511.

Figure 17. Charge capacity, Q, vs. number ot charge-discharge cycles for LaNi,95iCo07S Mn, AI(U electrodes [511.

Sarret P, Kitabgi P (2007) Neurotensin and receptors. The New Encyclopedia of Neuroscience (Lany squire et al., eds) in press... 

Fig. 8.13 Tetragonal crystal structures ofCaNi(BN) or LaNi(BN) (a) and La3Ni2(BN)2N (b), and MO scheme of [BN] (c). Nickel atoms (dark grey) are arranged in plane layers.

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