Methanation of CO2: Further insight into the mechanism over Rh/γ-Al2O3 catalyst

On the kinetics of the methanation of carbon dioxide on coprecipitated NiAl(O)

“…Nevertheless, they are strongly needed for reactor design and optimization and also for a qualified comparison of different catalyst systems. In view of economic feasibility we focused on Ni based systems though Rh [9][10][11], Ru [12][13][14][15][16] and Pd [17,18] have also been reported as catalytically active. Table 1 gives an overview of published models.…”

A novel W-doped Ni-Mg mixed oxide catalyst for CO2 methanation

“…Several efforts have been devoted to the development of effective and stable catalysts for this particular reaction since early 20th century [1,2]. Supported noble metal catalysts, such as Ru [3][4][5], Rh [6][7][8][9] and Pd [10][11][12] are well known for their excellent activity and stability in CO 2 methanation under relatively mild reaction conditions. Nevertheless, the large-scale application of these catalysts has been limited by their high cost.…”

Structure–function relationship during CO2 methanation over Rh/Al2O3 and Rh/SiO2 catalysts under atmospheric pressure conditions

“…39 The second mechanism involves the direct dissociation of CO 2 to CO(ads) and O(ads) on the metal surface, with CO(ads) being subsequently hydrogenated to CH 4 . 33,36,38,40 In our case the direct dissociation of CO 2 seems to be evidenced. We have confirmed experimentally that the first step in the mechanism by which the reaction occurs is dissociative adsorption of CO 2 on the surface of the catalyst.…”

“…These results are in agreement with previous reports suggesting the reduced Rh species to play an important role in the reaction mechanism. 36,38 By comparing the results obtained on a highly active catalyst (Rh/Al 2 O 3 ) to the ones obtained on a less active one (Rh/SiO 2 ), it can be concluded that the effect of the support on the methanation reaction for nonreducible oxides provides a high dispersion of the active phase. Some electronic interaction between the Rh and the support, influencing the bonding and the reactivity of the chemisorbed species, cannot be excluded and it is shown that the alumina support interacts with Rh facilitating the adsorption and dissociation of CO 2 .…”