Ni mesostructured catalysts obtained from rice husk ashes by microwave-assisted synthesis for CO2 methanation

Boosting the performance of Ni/Al2O3 for the reverse water gas shift reaction through formation of CuNi nanoalloys

“…In addition, Cu 2+ was detected with the peaks at 956.4 eV and 935.8 eV corresponding to Cu 2+ 2p 1/2 and 2p 3/2 , respectively 82,83 . The satellite components at 943 eV are generated through the O 2p to Cu 3d charge transfer effect in CuO 84,85 Please do not adjust margins Please do not adjust margins , corresponding to the catalyst with the higher Ni content, a small peak at 852.5 eV related to Ni 0 2p 3/2 could be detected 86 . Furthermore, XPS showed that only 9% of the Ni content is reduced, in agreement with the reduction degree of 13% at 500°C determined by H 2 -TPR in Ni/Al 2 O 3 .…”

“…Figure 3.b shows the spectra for the Ni 2p region. Only for Ni/Al 2 O 3, corresponding to the catalyst with the higher Ni content, a small peak at 852.5 eV related to Ni 0 2p 3/2 could be detected86 . Furthermore, XPS showed that only 9% of the Ni content is reduced, in agreement with the reduction degree of 13% at 500°C determined by H 2 -TPR in Ni/Al 2 O 3 .…”

Catalysts for the Conversion of CO2 to Low Molecular Weight Olefins—A Review

“…As expected, the ceria-modified catalyst showed increasingly better catalytic performance due to the effect of ceria limiting the growth of Fe 2 O 3 crystallites, weakening the interaction between Fe species and zirconia and facilitating the reduction in Fe species [133]. Hydrothermal treatment under microwave irradiation is also an effective method for support preparation, as demonstrated with the synthesis of mesocellular silica foam (MCF) from rice husk [134]. The nickel catalyst supported on this material exhibited high structure and catalytic stability, as well as resistance to coke formation in the hydrogenation reaction of CO 2 to methane [134].…”

“…The microwave technique is well known in catalysis because of the resulting higher dispersion of nanoparticles, but its use for the preparation of efficient catalysts for the formation of light olefins from CO 2 is scarce [35,133]. Microwave-assisted precipitation was successfully employed by Zhang et al for the preparation of Fe-Zn-K [35] and Fe-Zr-Ce-K [134] catalysts. The Fe-Zn-K catalysts were prepared by a microwave-assisted hydrothermal procedure followed by incipient wet impregnation.…”

“…Hydrothermal treatment under microwave irradiation is also an effective method for support preparation, as demonstrated with the synthesis of mesocellular silica foam (MCF) from rice husk [134]. The nickel catalyst supported on this material exhibited high structure and catalytic stability, as well as resistance to coke formation in the hydrogenation reaction of CO 2 to methane [134].…”