Power-to-Gas: Storing surplus electrical energy. Study of Al 2 O 3 support modification

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

“…Namely, γ-Al 2 O 3 structure favors metallic catalyst stability, activity and selectivity within the operation temperature range for this reaction, pointing to this support as one of the most suitable [27]. It has been shown in recent works that alumina support modification in Ni catalysts for the methane reaction increases activity, especially at low temperatures [19,28,29]. Liang et al described an increment in the conversion of CO 2 at low temperatures after the addition of magnesium (Mg), calcium (Ca), strontium (Sr), and barium (Ba) to the Ni/alumina catalysts, especially the last two [28].…”

“…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.…”

“…Alumina is the most common catalyst support, due to its high surface area which favors the dispersion of the metal atoms, facilitating the access of reaction gases to the active center [13][14][15][19][20][21][22][23]. Namely, γ-Al 2 O 3 structure favors metallic catalyst stability, activity and selectivity within the operation temperature range for this reaction, pointing to this support as one of the most suitable [27].…”

“…Cardenas-Arenas et al [29] prepared a 3D-ordered macroporous structure of NiO-CeO 2 mixed oxide (NiO-CeO 2 (np)) to achieve high CO 2 methanation conversion due to its high specific surface area if compared with a reference catalyst without size control (NiO-CeO 2 (Ref)). In addition, García-García et al [19] studied the addition of cerium (Ce) to modified alumina loading 4 and 6 wt% of Ce and 3 wt% zirconium (Zr) increasing the yield to methane at low temperature [19]. However, there were small amounts of Ce and Zr and it was observed that at least a 6 wt% of Ce is needed to improve the catalyst activity towards methanation.…”