Looking for an Optimal Composition of Nickel-Based Catalysts for CO2 Methanation

Abstract

A detailed critical analysis of the scientific literature data concerning catalysts for CO2 methanation based on nickel supported over oxides was performed. According to the obtained information, it seems that an ionic support is necessary to allow a good nickel dispersion to produce very small nickel metal particles. Such small metal particles result in being very active toward methanation, limiting the production of carbonaceous materials. The use of support and/or surface additives gives rise to medium surface basicity, allowing medium-strong adsorption of CO2, and it is also advisable to increase the reaction rate. A medium nickel loading would allow the free support geometric surface to be covered densely by small nickel metal particles without the production of larger Ni crystals. It is also advisable to work at temperatures where Ni(CO)4 formation is not possible (e.g., >573 K). The promising properties of systems based on doped Ni/Al2O3, doped with basic and re-active oxides such as MnOx or/and CeO2, and those based on Ni/CeO2 were underlined.

Mechanistic and Compositional Aspects of Industrial Catalysts for Selective CO2 Hydrogenation Processes

“…Nevertheless, the relatively strong adsorption of CO 2 over ionic oxides used as catalyst carriers, e.g., on aluminas doped with components with a basic character, such as Kdoped alumina [267], MgO-Al 2 O 3 [268] and La 2 O 3 /Al 2 O 3 [269] may have a role in CO 2 methanation. In fact, a positive effect of support basicity on CO 2 methanation on supported nickel has been reported [130].…”

“…A very large number of different catalyst compositions have been proposed in the literature for CO 2 methanation. A critical analysis of the scientific literature data concerning catalysts for CO 2 methanation allowed us to propose that Ni/Al 2 O 3 catalysts with medium metal loading allowing small metal particles to almost entirely cover the support surface, with additional ceria and/or basic oxide dopants as the stabilizers and activating components, would be very active in methanation and not produce many carbon residues and gums [130].…”

Improved Structural Description of Different γ-Al2O3 Materials Using Disordered δ5-Al2O3 Phase via X-ray Pair Distribution Function Analysis

“…In the quest for efficient heterogeneous catalysts, nanostructured γ-Al 2 O 3 has garnered considerable attention as a highly stable support material. Its high industrial relevance is reflected in its usage across various catalytic processes [1][2][3]. While α-Al 2 O 3 is the thermodynamically most stable modification, its comparably small specific surface of ca.…”