4.1 Hydrogen Sulfide Decomposition
39
chalcogens, activated carbon, and perovskites of transition and rare earth metals are
also used for the purpose. Fluidized catalysts have shown better catalytic activities
as compared to the bed catalysts due to the enhanced cleaning effect on the surface
of catalyst and improved intraparticle mass transfer [10–12].
H 2 S molecule can also be dissociated into sulfur and sustainable hydrogen via
electrochemistry technique. In this process, the hydrogen is liberated at cathode
(reduction reaction) where sulfur is obtained at anode (oxidation reaction), and the
deposition of the sulfur at anode also results in the severe passivation of anode.
Therefore, heat is used in the electrochemical assembly for the transfer of sulfur into
sulfur steam [13]. The chemical reactions for the process can be given as.
H 2 S + 2e
−
→ H 2 + S
2−
(reduction half reaction).
S
2−
→ S + 2e
−
(oxidation reaction)
H 2 S
−
→ H 2 + S
(overall reaction)
Multistep thermochemical processes are also available for the decomposition of
H 2 S to generate H 2 . These processes involve two-step mechanism depending upon
H 2 S adsorption (via a single metal or group of metals) and methods that are taken
from water splitting reactions. The well-known multistep thermochemical processes
for decomposition of H 2 S are sulfurization of metals, inorganic sulfides or oxides,
thermochemical sulfur–iodine cycles, and revamping of CO or COS cycles [14–16].
Several H 2 S decomposition processes involve the use of nanotechnology. The
common nanomaterial involved in the dissociation of H 2 S molecule involves the
transition metal-based nanomaterials such as nanoparticles of different Cd chalcogens. Some carbon- based nanomaterials such as graphene oxide (GO) powder also
involve in the decomposition of the compound. The current chapter will explain the
frequently used nanomaterials in H 2 S decomposition for the generation of sustainable
hydrogen.
4.2 Cadmium-Based Nanomaterials and Hydrogen Sulfide
Decomposition
Cd salts with different materials, particularly sulfur, are used as the catalyst for
the conversion of H 2 S to H 2 . However, they are susceptible to photo-corrosion.
Different studies have suggested different solutions to the problem. In a study, the
nano-CdS powder was synthesized in hetero-matrix solid-state polymer-inorganic
reaction. The nano-CdS powder eliminated the problem of photo-corrosion along
with the improved photocatalytic ability due to the presence of charge transfer. These
thermally stable nanocrystallites of CdS restrained on polyphenylene sulfide (PPS)
39
chalcogens, activated carbon, and perovskites of transition and rare earth metals are
also used for the purpose. Fluidized catalysts have shown better catalytic activities
as compared to the bed catalysts due to the enhanced cleaning effect on the surface
of catalyst and improved intraparticle mass transfer [10–12].
H 2 S molecule can also be dissociated into sulfur and sustainable hydrogen via
electrochemistry technique. In this process, the hydrogen is liberated at cathode
(reduction reaction) where sulfur is obtained at anode (oxidation reaction), and the
deposition of the sulfur at anode also results in the severe passivation of anode.
Therefore, heat is used in the electrochemical assembly for the transfer of sulfur into
sulfur steam [13]. The chemical reactions for the process can be given as.
H 2 S + 2e
−
→ H 2 + S
2−
(reduction half reaction).
S
2−
→ S + 2e
−
(oxidation reaction)
H 2 S
−
→ H 2 + S
(overall reaction)
Multistep thermochemical processes are also available for the decomposition of
H 2 S to generate H 2 . These processes involve two-step mechanism depending upon
H 2 S adsorption (via a single metal or group of metals) and methods that are taken
from water splitting reactions. The well-known multistep thermochemical processes
for decomposition of H 2 S are sulfurization of metals, inorganic sulfides or oxides,
thermochemical sulfur–iodine cycles, and revamping of CO or COS cycles [14–16].
Several H 2 S decomposition processes involve the use of nanotechnology. The
common nanomaterial involved in the dissociation of H 2 S molecule involves the
transition metal-based nanomaterials such as nanoparticles of different Cd chalcogens. Some carbon- based nanomaterials such as graphene oxide (GO) powder also
involve in the decomposition of the compound. The current chapter will explain the
frequently used nanomaterials in H 2 S decomposition for the generation of sustainable
hydrogen.
4.2 Cadmium-Based Nanomaterials and Hydrogen Sulfide
Decomposition
Cd salts with different materials, particularly sulfur, are used as the catalyst for
the conversion of H 2 S to H 2 . However, they are susceptible to photo-corrosion.
Different studies have suggested different solutions to the problem. In a study, the
nano-CdS powder was synthesized in hetero-matrix solid-state polymer-inorganic
reaction. The nano-CdS powder eliminated the problem of photo-corrosion along
with the improved photocatalytic ability due to the presence of charge transfer. These
thermally stable nanocrystallites of CdS restrained on polyphenylene sulfide (PPS)