Two-dimensional molybdenum carbide 2D-Mo<sub>2</sub>C as a superior catalyst for CO<sub>2</sub> hydrogenation.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 34535647.
- Also identified by DOI 10.1038/s41467-021-25784-0 and PMC identifier 8448824.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Early transitional metal carbides are promising catalysts for hydrogenation of CO<sub>2</sub>. Here, a two-dimensional (2D) multilayered 2D-Mo<sub>2</sub>C material is prepared from Mo<sub>2</sub>CT<sub>x</sub> of the MXene family. Surface termination groups T<sub>x</sub> (O, OH, and F) are reductively de-functionalized in Mo<sub>2</sub>CT<sub>x</sub> (500 °C, pure H<sub>2</sub>) avoiding the formation of a 3D carbide structure. CO<sub>2</sub> hydrogenation studies show that the activity and product selectivity (CO, CH<sub>4</sub>, C<sub>2</sub>-C<sub>5</sub> alkanes, methanol, and dimethyl ether) of Mo<sub>2</sub>CT<sub>x</sub> and 2D-Mo<sub>2</sub>C are controlled by the surface coverage of T<sub>x</sub> groups that are tunable by the H<sub>2</sub> pretreatment conditions. 2D-Mo<sub>2</sub>C contains no T<sub>x</sub> groups and outperforms Mo<sub>2</sub>CT<sub>x</sub>, β-Mo<sub>2</sub>C, or the industrial Cu-ZnO-Al<sub>2</sub>O<sub>3</sub> catalyst in CO<sub>2</sub> 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<sub>2</sub> hydrogenation.