6.2 Nanohydride-Based Hydrogen Generation
65
process. 400 mL/min/g of hydrogen was achieved from 10 wt.% solution of NaBH 4
with 5 wt. % NaOH at 35 °C 5 wt. % NaOH using the fabricated nanocatalysts [25].
As mentioned earlier, Al and the Al-based alloys are very significant in the generation of hydrogen. Nanocrystalline Al hydrides also known as alanates are very
significant hydrogen storage substances for proton exchange membrane fuel cell
applications. In order to use the alanates for the hydrogen storage or generation
applications, several factors like amount of reversible hydrogen, thermodynamic and
kinetic parameters have to be optimized. Ti catalysts have seen to improve the uptake
and release of kinetics of hydrogen. In an investigation, different nanocrystalline Al
hydrides like magnesium alanate Mg (AlH 4 ) 2 have been synthesized which contains
9.3 wt.% calculated amount of hydrogen. The fabricated alanate when allowed to
decompose at ~160 °C, the three-fourth of the hydrogen is generated, and the last
part of the hydrogen can also be obtained at temperatures as high as 300 °C, which
is not suitable for proton exchange membrane fuel purposes. The chemical reaction
for the process can be given as.
MgH 2 → Mg + H 2
Afterward, the Mg reacts with Al to give the following reaction:
Mg + 2Al → 12Al 3 Mg 2 + 12Al
The formation of the intermetallic compound is confirmed by the XRD analysis.
The equations give the rough estimation of the decomposition of the material [26].
Nanoclusters of intrazeolite cobalt were used in an investigation for the hydrogen
liberation from sodium borohydride. The nanoclusters were fabricated via the ionexchange method. In practice, the Na
+ ions of the zeolite were exchanged by the
Co
2+ ions, followed by the subsequent reduction (of Co
2+ ions inside the zeolite-Y)
with NaBH 4 as imitator at room temperature. The product thus formed was separated
as solid material. The formed product was analyzed with XRD, inductively coupled
plasma optical emission spectrometry (ICP-OES), SEM, TEM, XPS, Raman spectroscopy, and N 2 adsorption technique. The nanoclusters were evaluated for their
catalytic activity in the hydrolysis of sodium borohydride solution with and without
the base. The nanoclusters have depicted better results in the basic solution. The
study reported the record production turnover of hydrogen from the hydrolysis of
the sodium borohydride in alkaline solution [27].
Nurettin et al. have reported the use of ruthenium and magnetic iron nanoparticles
as the catalyst for the hydrolysis of NaBH 4 . The nanoparticles in the study were used
in the form of composites on the hydrogel matrix. The hydrogels were prepared from -
acrylamido-2-methyl-1-propansulfonic acid, N, N
-methylenebisacrylamide (MBA),
and 2,2
-azobis(2-methylpropionamidine) dihydrochloride as monomer, crosslinker,
and UV initiator, respectively. The resulting hydrogel is pH sensitive, hydrophilic,
and have the ability to absorb the metal ions. The Ru and Fe nanoparticles inside
the hydrogels were prepared separately. The prepared product was characterized
with TEM. The study found have that the repetitive use of the prepared material
65
process. 400 mL/min/g of hydrogen was achieved from 10 wt.% solution of NaBH 4
with 5 wt. % NaOH at 35 °C 5 wt. % NaOH using the fabricated nanocatalysts [25].
As mentioned earlier, Al and the Al-based alloys are very significant in the generation of hydrogen. Nanocrystalline Al hydrides also known as alanates are very
significant hydrogen storage substances for proton exchange membrane fuel cell
applications. In order to use the alanates for the hydrogen storage or generation
applications, several factors like amount of reversible hydrogen, thermodynamic and
kinetic parameters have to be optimized. Ti catalysts have seen to improve the uptake
and release of kinetics of hydrogen. In an investigation, different nanocrystalline Al
hydrides like magnesium alanate Mg (AlH 4 ) 2 have been synthesized which contains
9.3 wt.% calculated amount of hydrogen. The fabricated alanate when allowed to
decompose at ~160 °C, the three-fourth of the hydrogen is generated, and the last
part of the hydrogen can also be obtained at temperatures as high as 300 °C, which
is not suitable for proton exchange membrane fuel purposes. The chemical reaction
for the process can be given as.
MgH 2 → Mg + H 2
Afterward, the Mg reacts with Al to give the following reaction:
Mg + 2Al → 12Al 3 Mg 2 + 12Al
The formation of the intermetallic compound is confirmed by the XRD analysis.
The equations give the rough estimation of the decomposition of the material [26].
Nanoclusters of intrazeolite cobalt were used in an investigation for the hydrogen
liberation from sodium borohydride. The nanoclusters were fabricated via the ionexchange method. In practice, the Na
+ ions of the zeolite were exchanged by the
Co
2+ ions, followed by the subsequent reduction (of Co
2+ ions inside the zeolite-Y)
with NaBH 4 as imitator at room temperature. The product thus formed was separated
as solid material. The formed product was analyzed with XRD, inductively coupled
plasma optical emission spectrometry (ICP-OES), SEM, TEM, XPS, Raman spectroscopy, and N 2 adsorption technique. The nanoclusters were evaluated for their
catalytic activity in the hydrolysis of sodium borohydride solution with and without
the base. The nanoclusters have depicted better results in the basic solution. The
study reported the record production turnover of hydrogen from the hydrolysis of
the sodium borohydride in alkaline solution [27].
Nurettin et al. have reported the use of ruthenium and magnetic iron nanoparticles
as the catalyst for the hydrolysis of NaBH 4 . The nanoparticles in the study were used
in the form of composites on the hydrogel matrix. The hydrogels were prepared from -
acrylamido-2-methyl-1-propansulfonic acid, N, N
-methylenebisacrylamide (MBA),
and 2,2
-azobis(2-methylpropionamidine) dihydrochloride as monomer, crosslinker,
and UV initiator, respectively. The resulting hydrogel is pH sensitive, hydrophilic,
and have the ability to absorb the metal ions. The Ru and Fe nanoparticles inside
the hydrogels were prepared separately. The prepared product was characterized
with TEM. The study found have that the repetitive use of the prepared material