Reduced graphene oxide supported Ni-Ce catalysts for CO2 methanation: The support and ceria promotion effects

Effect of the Addition of Alkaline Earth and Lanthanide Metals for the Modification of the Alumina Support in Ni and Ru Catalysts in CO2 Methanation

“…The diffraction peaks of the support observed in the XRD pattern after using the catalysts in the methane reaction up to 773 K, with a current containing H2S, do not show significant variations. The addition of La, Ce, and Ba to the Ni/Al 2 O 3 catalysts produces the damping of the Ni reflection peaks, due to the dispersion of the metal in the support [17,28,29]. The catalyst with Ce has a similar XRD pattern before and after participating in the reaction, identifying the diffraction peaks of CeO 2 in both spectra.…”

“…In the case of metal promoters, Ni and Ru are in their metallic form both in the reduced fresh and used catalysts, their oxidized form not being detected. Ni peaks are observed at 44.5° (111), 51.6° (200), and 76.7° (220)[17]. In the case of Ru, the main peak is shown at 44.2° (101), the…”

“…Some of the metals that have proven to be active in methane production are noble metals such as ruthenium (Ru), rhodium (Rh), and palladium (Pd), but also nickel (Ni), and their combinations [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]. The most commonly used supports in the literature for the dispersion of these metals are metal oxides such as Al 2 O 3 , SiO 2 , TiO 2 , CeO 2 , zeolites (among others) and even, in recent works, reduced graphene oxide (rGO) [12][13][14][15][16][17][18][19][20][21][22]. Nickel-based catalysts are common in the literature due to their competitive activity and low price, being proposed as a viable alternative to noble metals [10,13,[17][18][19]21,23].…”

“…The most commonly used supports in the literature for the dispersion of these metals are metal oxides such as Al 2 O 3 , SiO 2 , TiO 2 , CeO 2 , zeolites (among others) and even, in recent works, reduced graphene oxide (rGO) [12][13][14][15][16][17][18][19][20][21][22]. Nickel-based catalysts are common in the literature due to their competitive activity and low price, being proposed as a viable alternative to noble metals [10,13,[17][18][19]21,23]. However, in order to verify the effect that the noble metal has on Ni, Mihet M. and Lazar M.D.…”

In Vitro Electrochemical Behavior of Sol‐Gel Derived Hydroxyapatite/Graphene Oxide Composite Coatings on 316L SS for Biomedical Applications

“…Graphene oxide was extensively used in several fields by many researchers owing to their widespread properties such as extraordinary thermal consistency, electrical conductivity and transportation, anti-corrosive properties, energy storage in battery and super capacitor products, electrochemical sensor applications in human trails (biosensors) and quality control applications, photocatalytic properties which used in the conversion of CO 2 to commercially usable products such as ethanol, acetic acid and methane etc, bio-imaging for the detection of tumors, further used as nano drug carriers for targeted drug delivery systems and also possesses their well proved high mechanical strength with flexibility. [15][16][17][18][19][20][21][22][23][24] Accordingly, the hardness and fracture durability of the HAP can be enhanced by making composite with graphene oxide, which improves the properties of HAP suitable for higher load posture prosthesis. In contrast, graphene oxide consists of different functional groups such as epoxy groups, hydroxyl (À OH) and keto groups on their sidewalls, which keeps it highly hydrophilic.…”