Work

Mo2Ti2C3TX MXene performance in catalytic CO2 hydrogenation and its promotion with single Pt atoms

Year: 2024

Type: article

Abstract: Mo 2 Ti 2 C 3 T x MXene materials, bare or loaded with strongly anchored single Pt atoms, were investigated using various methods, including STEM, XPS , XAS and DFT calculations . Upon Pt impregnation, the delaminated Mo-rich MXene surface undergoes partial oxidation , which is reversed by an H 2 thermal treatment at 400 °C. The optimized MXene shows high catalytic activity for CO 2 hydrogenation to CO and smaller amounts of methane and methanol. Around and above the pretreatment temperature of 400 °C, the MXene is gradually defunctionalized from O- and F-containing groups and depleted in carbidic carbon, leading to deactivation. Single Pt atoms are cationic after impregnation, and reduce upon H 2 treatment, filling surface Mo vacancies. Pt addition increases the MXene activity, in particular by facilitating H 2 dissociation, but has little effect on the single-atom catalyst selectivity and on the rate dependence upon reactant partial pressures . The lowest Pt loading leads to the highest turnover frequency , indicating that the MXene surface sites are key to CO 2 activation.

Source: Materials Today Catalysis

DOI: 10.1016/j.mtcata.2024.100069