Two-dimensional molybdenum carbide 2D-Mo2C as a superior catalyst for CO2 hydrogenation
Hui Zhou, Zixuan Chen, Evgenia Kountoupi, Athanasia Tsoukalou, Paula M. Abdala, Pierre Florian, Alexey Fedorov, Christoph R. Müller
Abstract
Abstract Early transitional metal carbides are promising catalysts for hydrogenation of CO 2 . Here, a two-dimensional (2D) multilayered 2D-Mo 2 C material is prepared from Mo 2 C T x of the MXene family. Surface termination groups T x (O, OH, and F) are reductively de-functionalized in Mo 2 C T x (500 °C, pure H 2 ) avoiding the formation of a 3D carbide structure. CO 2 hydrogenation studies show that the activity and product selectivity (CO, CH 4 , C 2 –C 5 alkanes, methanol, and dimethyl ether) of Mo 2 C T x and 2D-Mo 2 C are controlled by the surface coverage of T x groups that are tunable by the H 2 pretreatment conditions. 2D-Mo 2 C contains no T x groups and outperforms Mo 2 C T x , β-Mo 2 C, or the industrial Cu-ZnO-Al 2 O 3 catalyst in CO 2 hydrogenation (evaluated by CO weight time yield at 430 °C and 1 bar). We show that the lack of surface termination groups drives the selectivity and activity of Mo-terminated carbidic surfaces in CO 2 hydrogenation.