Two-dimensional Molybdenum Carbide 2D-Mo2c As a Superior Catalyst for CO2 Hydrogenation

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.