NiFe₂O₄ Nanoparticles Catalytic Effects of Improving LiAlH₄ Dehydrogenation Properties

Abstract

The effects of NiFe 2 O 4 nanoparticles addition on the dehydrogenation behavior of LiAlH 4 were investigated. The onset dehydrogenation temperature for LiAlH 4 +3 mol % NiFe 2 O 4 sample is 61°C, which decreased by 94°C compared with the as-received LiAlH 4 and released ∼7.2 wt % hydrogen when heated to 180°C. Isothermal desorption measurements show that the 3 mol % NiFe 2 O 4 -doped sample releases ∼7.0 wt % of hydrogen in 91 min at 120°C, which is 6.3 wt % higher than the as-received LiAlH 4 under the same conditions. Through calculating the apparent activation energy of the LiAlH 4 samples with and without NiFe 2 O 4 for the first two dehydrogenation stages, the E a of the LiAlH 4 +3 mol % NiFe 2 O 4 sample is 54.3 and 70.8 kJ/mol, resulting in 52.5 and 59% decrease, respectively, compared with the as-received LiAlH 4 . Analyzing the X-ray diffraction and Fourier transform infrared spectroscopy results, it is reasonable to believe that the remarkable improvement of dehydrogenation properties of NiFe 2 O 4 -doped LiAlH 4 results from the in situ formed LiFeO 2 and Al−Ni compounds, providing the active sites for nucleation and growth of the dehydrogenation products.

Enhanced hydrogen storage properties of LiAlH4 catalyzed by CoFe2O4 nanoparticles

“…In the XRD spectra of the as-milled LiAlH 4 all diffraction peaks correspond to the LiAlH 4 phase, without any additional decomposition products, suggesting that pure LiAlH 4 remains rather stable during the ball milling process. [13][14][15][16]18,40,43,57,58 This point can also be proven by the nonisothermal dehydrogenation properties of the as-received and as-milled LiAlH 4 (Fig. 1), and the FTIR spectra of the as-milled LiAlH 4 (Fig.…”

“…To date, the documented catalysts for LiAlH 4 can be classied as: (1) 18,20 (5) metal oxides [14][15][16]43,44 and (6) other compounds.…”

Improved hydrogen storage properties of LiAlH4 by mechanical milling with TiF3

“…At present, a lot of research has been carried out on doping modification. LiAlH 4 starts to decompose at 61 C with 3 mol % NiFe 2 O 4 as an additive and releases 7.2 wt % H 2 at 180 C [19]. Balema et al mechanically ball milled LiAlH 4 -3 mol % TiCl 4 at room temperature for 5 min, and then LiAlH 4 has completely broken down to Li 3 AlH 6 , Al and H 2 [20].…”

Magnetic nickel ferrite nanoparticles as an efficient catalyst for the preparation of polyhydroquinoline derivatives under microwave irradiation in solvent-free conditions

“…Nickel ferrite MNPs are inexpensive, air-stable, magnetically separable, and economical catalysts [41][42][43][44]. There are very limited and there are less references about catalytic properties of nickel ferrite MNPs [45][46][47]. These spinel-type bimetal oxides, have shown great potential in the field of use for catalysis, although they have so far been less investigated.…”