Chapter 6
Hydrogen from Miscellaneous Sources
and Nanotechnology
6.1 Introduction
Apart from the sources mentioned in the previous chapters, there are several other
important substances that generate H 2 upon chemical or physical treatment. For
instance, when aluminum and NaOH are allowed to react they result in the generation
of hydrogen. Al is the most abundantly found crustal metal. The metal can be fully
recycled, and hence is also called as “viable metal.” Al is a very lightweight metal
which has several characteristics for being used in the generation of sustainable
energy. It is also used in energy storage batteries. When employed with highly alkaline
electrolyte the reduction potential of pure Al can be as low as −2.33 V relative to the
standard hydrogen potential [1]. The formation of hydrogen in corrosion reaction of
Al leads to the use of Al in generation of sustainable hydrogen. Aluminum-based
generation of hydrogen requires 2% energy and the emission of carbon dioxide is 4%
of the amount generated by the traditional methods of hydrogen generation. Al and
Al-based alloys are excellent candidates of onboard vehicle hydrogen generation [2].
In strongly alkaline solution, the hydroxide ions (OH
− ) are generated. These ions
are capable of destroying the protective layer of the oxide formed on the surface
aluminum, resulting in the formation of AlO 2
− . Because of this the Al and the Albased alloys dissolved readily in the alkaline solutions. The reaction of the Al with
alkalis occurs at room temperature resulting in the formation of hydrogen. In the
chemical reactions below, it is shown that how Al reacts with NaOH (a strong alkali)
for generation of hydrogen [3].
2Al + 6H 2 O + 2NaOH → 2NaAl(OH) 4 + 3H 2
NaAl(OH) 4 → NaOH + Al(OH)
2Al + 6H 2 O → 2Al(OH) 3 + 3H 2
© The Editor(s) (if applicable) and The Author(s), under exclusive license
to Springer Nature Switzerland AG 2021
S. Farrukh et al., Nanotechnology and the Generation of Sustainable Hydrogen,
Green Energy and Technology, https://doi.org/10.1007/978-3-030-60402-8_6
61
Hydrogen from Miscellaneous Sources
and Nanotechnology
6.1 Introduction
Apart from the sources mentioned in the previous chapters, there are several other
important substances that generate H 2 upon chemical or physical treatment. For
instance, when aluminum and NaOH are allowed to react they result in the generation
of hydrogen. Al is the most abundantly found crustal metal. The metal can be fully
recycled, and hence is also called as “viable metal.” Al is a very lightweight metal
which has several characteristics for being used in the generation of sustainable
energy. It is also used in energy storage batteries. When employed with highly alkaline
electrolyte the reduction potential of pure Al can be as low as −2.33 V relative to the
standard hydrogen potential [1]. The formation of hydrogen in corrosion reaction of
Al leads to the use of Al in generation of sustainable hydrogen. Aluminum-based
generation of hydrogen requires 2% energy and the emission of carbon dioxide is 4%
of the amount generated by the traditional methods of hydrogen generation. Al and
Al-based alloys are excellent candidates of onboard vehicle hydrogen generation [2].
In strongly alkaline solution, the hydroxide ions (OH
− ) are generated. These ions
are capable of destroying the protective layer of the oxide formed on the surface
aluminum, resulting in the formation of AlO 2
− . Because of this the Al and the Albased alloys dissolved readily in the alkaline solutions. The reaction of the Al with
alkalis occurs at room temperature resulting in the formation of hydrogen. In the
chemical reactions below, it is shown that how Al reacts with NaOH (a strong alkali)
for generation of hydrogen [3].
2Al + 6H 2 O + 2NaOH → 2NaAl(OH) 4 + 3H 2
NaAl(OH) 4 → NaOH + Al(OH)
2Al + 6H 2 O → 2Al(OH) 3 + 3H 2
© The Editor(s) (if applicable) and The Author(s), under exclusive license
to Springer Nature Switzerland AG 2021
S. Farrukh et al., Nanotechnology and the Generation of Sustainable Hydrogen,
Green Energy and Technology, https://doi.org/10.1007/978-3-030-60402-8_6
61