The effects of nanometric nickel (n-Ni) catalyst on the dehydrogenation and rehydrogenation behavior of ball milled lithium alanate (LiAlH4)

NiFe2O4 Nanoparticles Catalytic Effects of Improving LiAlH4 Dehydrogenation Properties

“…While compared with the as-received LiAlH 4 , the onset desorption temperatures for the as-milled LiAlH 4 both decrease by 21°C at the first two dehydrogenation steps, attributed to the decrease in LiAlH 4 grain size by mechanical milling. 8,23,26,29,31 After doping the NiFe 2 O 4 nanoparticles into the LiAlH 4 matrix, the dehydrogenation process for the LiAlH 4 +1 mol % NiFe 2 O 4 sample starts at 68°C. With increasing the NiFe 2 O 4 proportion to 3 mol %, the onset decomposition temperature further decreases to 61°C, which shows a 94°C decrease, compared with that of the asreceived LiAlH 4 .…”

“…Nevertheless, many efforts have been devoted to solve the crucial LiAlH 4 drawbacks for practical applications, corresponding to high thermodynamic stability and slow desorption kinetics by doping various catalysts. To date, the documented catalysts for LiAlH 4 fall into six categories: (1) elemental metal, such as Ni, 7,8 Fe, 7,9,10 V, 7,14 Sc, 14 and Ti; 7,10−14 (2) (6) and others, such as nanosized TiH 2 , 33 Ce(SO 4 ) 2 , 34 VCl 3 and CNFs, 15 SWCNT-metallic, 35 and TiN. 4 Most of these catalysts do not work with LiAlH 4 as a suitable hydrogen-storage medium.…”

Thermodynamics study of hydrogen storage materials

“…This is quite attractive for fuel cell application. The first step in the dehydrogenation of NbF 5 -doped LiAlH 4 was found to be exothermic (figure 2c), which was also observed when the additives changed into TiF 3 [7], Al 3 Ti [8], Ni [9], or TiC [10]. However, it is not always the case.…”

Synthesis of LiAlH4 Nanoparticles Leading to a Single Hydrogen Release Step upon Ti Coating

“…For hydrogen storage purposes, LiAlH 4 is one of the most promising and interesting candidates owing to its competitive total hydrogen capacity as well as its low temperature for hydrogen release with fast kinetics [3,6]. When doped with catalysts, about 75% of its stored hydrogen can be released below 100 • C in about 1.5 h, while 30 min is required when at 150 • C [7][8][9][10][11]. A particularity of LiAlH 4 is the exothermic nature of its initial hydrogen release following the widely accepted Steps 1-3 [12][13][14].…”

“…Hence, upon mechanically milling LiAlH 4 with TiCl 3 , ZrCl 4 , or nanosized Ni, lower hydrogen desorption temperatures have been achieved [7][8][9][10][11]; however, with no successful rehydrogenation. Indirect rehydrogenation routes have also been demonstrated through the use of wet synthesis approaches involving the formation of solvent adducts of LiAlH 4 -i.e., THF, Et 2 O, diglyme, and Me 2 O-and in most cases activated/catalyzed Al [12][13][14][15][16].…”