3.3 Partial Oxidation
29
This ZrO 2 /SiO 2 was synthesized by sol–gel coating process. The prepared material
has average diameter of ~ 10 nm. The silica structure was prepared with pluronic,
trimethylbenzene, and tetraethoxysilane. The prepared honeycomb-like assembly
of the silica was modified with zirconium n-propoxide, and glacial acetic acid, in
order to add the ZrO 2 encasing. Afterward, dispersed Ni nanoparticles were incorporated on ZrO 2 /SiO 2 assembly by impregnation method by using Ni (NO 3 ) 2 · 6H 2 O.
The prepared catalysts were analyzed with N 2 adsorption–desorption, TEM, SEM,
H 2 -TPR/TPD, TGA, and XRD. The fabricated nanocatalyst depicted better coking
and anti-sintering ability in comparison to the traditional counterparts. The rate
of methane conversion by employing honeycomb ZrO 2 /SiO 2 -Ni was found to be
90–92%. This superior performance of these catalysts is associated with the better
metal dispersion in three-dimensional honeycomb SiO 2 , thermal stability of the Ni
nanoparticles, and the multiple interfaces between Ni, ZrO 2 , and honeycomb support
[7].
Marin et al. have reported the partial oxidation of Jet-A fuels to hydrogen and
carbon monoxide via nanoparticle of MoO 2 . These nanoparticles were prepared
by the reduction of MoO 3 in 1:3 by volume solution of ethylene glycol and distilled
water. The prepared nanoparticle MoO 2 was analyzed with XRD, SEM, BET, and Xray photoelectron spectroscopy (XPS). MoO 2 nanoparticles depicted ∼99% conversion of the fuel (at 850 °C, 1 atm) and ∼60% yield of hydrogen. In the similar study,
the MoO 2 catalyst was compared with the reference Ni catalyst at similar conditions
which was deactivated because of coking in less than 4 h of the process where MoO 2
nanoparticles showed a 10-h coking resistance [8].
Ni nanoparticles are known for their ability to partially oxidize methane to
generate hydrogen. In a study conducted in 2019, the stability of the Ni nanocatalysts was enhanced by using the reactive oxygen species (ROS) in certain metal
oxides. The Ni nanoparticles were immobilized inside the different mesoporous
metal oxides such as Yb 2 O 3 , La 2 O 3 , CeO 2 , and ZrO 2 . This was done via evaporationinduced self-assembly method by utilizing honeycomb-like silica as substrate. The
honeycomb-like silica structure was synthesized with pluronic, trimethylbenzene,
and tetraethoxysilane, and the mesoporous oxides were formed with propoxide of
the particular metal oxide, glacial acetic acid, and hydrochloric acid. Later on, the
Ni catalyst was immobilized on them by wet impregnation method via Ni (NO 3 ) 2
· 6H 2 O. The highly activated nanoparticles were characterized with TEM, SEM,
and H 2 -TPR. The metal oxide-supported Ni nanocatalysts showed superior catalytic
stability, and this stability can be attributed to the strong interaction between Ni and
metal oxides, high dispersion of the active metal, and the confinement effect. By
using these enhanced catalysts, 90–92% methane conversion was achieved. Abundant hydrogen production was reported by the use of this improved Ni nanocatalyst
via partial oxidation of methane [9].
The catalytic activity of the Pt nanoparticles was improved by confining them on
pores of silicalite-1 zeolite. Lichao et al. synthesized these improved Pt nanoparticles for the partial oxidation of methane to syngas (a mixture of fuel gases with
29
This ZrO 2 /SiO 2 was synthesized by sol–gel coating process. The prepared material
has average diameter of ~ 10 nm. The silica structure was prepared with pluronic,
trimethylbenzene, and tetraethoxysilane. The prepared honeycomb-like assembly
of the silica was modified with zirconium n-propoxide, and glacial acetic acid, in
order to add the ZrO 2 encasing. Afterward, dispersed Ni nanoparticles were incorporated on ZrO 2 /SiO 2 assembly by impregnation method by using Ni (NO 3 ) 2 · 6H 2 O.
The prepared catalysts were analyzed with N 2 adsorption–desorption, TEM, SEM,
H 2 -TPR/TPD, TGA, and XRD. The fabricated nanocatalyst depicted better coking
and anti-sintering ability in comparison to the traditional counterparts. The rate
of methane conversion by employing honeycomb ZrO 2 /SiO 2 -Ni was found to be
90–92%. This superior performance of these catalysts is associated with the better
metal dispersion in three-dimensional honeycomb SiO 2 , thermal stability of the Ni
nanoparticles, and the multiple interfaces between Ni, ZrO 2 , and honeycomb support
[7].
Marin et al. have reported the partial oxidation of Jet-A fuels to hydrogen and
carbon monoxide via nanoparticle of MoO 2 . These nanoparticles were prepared
by the reduction of MoO 3 in 1:3 by volume solution of ethylene glycol and distilled
water. The prepared nanoparticle MoO 2 was analyzed with XRD, SEM, BET, and Xray photoelectron spectroscopy (XPS). MoO 2 nanoparticles depicted ∼99% conversion of the fuel (at 850 °C, 1 atm) and ∼60% yield of hydrogen. In the similar study,
the MoO 2 catalyst was compared with the reference Ni catalyst at similar conditions
which was deactivated because of coking in less than 4 h of the process where MoO 2
nanoparticles showed a 10-h coking resistance [8].
Ni nanoparticles are known for their ability to partially oxidize methane to
generate hydrogen. In a study conducted in 2019, the stability of the Ni nanocatalysts was enhanced by using the reactive oxygen species (ROS) in certain metal
oxides. The Ni nanoparticles were immobilized inside the different mesoporous
metal oxides such as Yb 2 O 3 , La 2 O 3 , CeO 2 , and ZrO 2 . This was done via evaporationinduced self-assembly method by utilizing honeycomb-like silica as substrate. The
honeycomb-like silica structure was synthesized with pluronic, trimethylbenzene,
and tetraethoxysilane, and the mesoporous oxides were formed with propoxide of
the particular metal oxide, glacial acetic acid, and hydrochloric acid. Later on, the
Ni catalyst was immobilized on them by wet impregnation method via Ni (NO 3 ) 2
· 6H 2 O. The highly activated nanoparticles were characterized with TEM, SEM,
and H 2 -TPR. The metal oxide-supported Ni nanocatalysts showed superior catalytic
stability, and this stability can be attributed to the strong interaction between Ni and
metal oxides, high dispersion of the active metal, and the confinement effect. By
using these enhanced catalysts, 90–92% methane conversion was achieved. Abundant hydrogen production was reported by the use of this improved Ni nanocatalyst
via partial oxidation of methane [9].
The catalytic activity of the Pt nanoparticles was improved by confining them on
pores of silicalite-1 zeolite. Lichao et al. synthesized these improved Pt nanoparticles for the partial oxidation of methane to syngas (a mixture of fuel gases with