3558259

In-situ X-ray absorption spectroscopy study of electrocatalytic reduction of carbon dioxide with molybdenum disulfide


Session: General Catalysis:  

Electrocatalytic reactions offer alternative routes for the conversion and storage of energy. For instance, the electrocatalytic reduction of carbon dioxide could lead to energy-rich syngas, methanol, or even hydrocarbons. Layered transition metal dichalcogenide nanomaterials, such as MoS2, have emerged as electrocatalysts towards CO2 reduction with high efficiency and low overpotentials. However, the underlying chemical and electronic states defining the catalytic activity have not yet been completely defined. These key states can be probed for both metals and ligands in selected MX2 (M=W, Mo; X=S, Se) using synchrotron-based X-ray absorption spectroscopy (XAS). In the recent work we performed in-situ XAS measurements at Mo K-edge and S K-edge for MoS2 nanosheets. Measurements at sulfur K-edge showed drastic changes at the pre-edge and edge indicating changes in number of available occupied states and Zeff respectively, on the other hand Mo K-edge showed only a slight shift. Metal d-states are found to be the active site for the catalysis, ligand K-edge presents a better method to examine catalytic processes as the pre-edge reflects a transition to metal-ligand hybridized states, hence pre-edge intensity and position gives insight into the active metal d states. Given the vast compositional space of metal and ligand for MX2, the knowledge of how d-state activity will serve to pave the way to a better study of metal and chalcogenide combinations to improve the electrocatalytic performance.

Presenter

Speakers


Related Products

Thumbnail for Determination of oxidation state and symmetry of Fe from X-ray absorption spectroscopy spectra using machine learning
Determination of oxidation state and symmetry of Fe from X-ray absorption spectroscopy spectra using machine learning
X-ray absorption spectroscopy (XAS) is a technique used to probe unoccupied electronic states by exciting core electrons. The absorption energy of a photon by a transition metal varies depending on the binding energy of the excited electron…
Thumbnail for Beyond traditional layered oxides: Exploration of the flexibility of anion lattices to unlock novel Li-ion battery cathodes
Beyond traditional layered oxides: Exploration of the flexibility of anion lattices to unlock novel Li-ion battery cathodes
The capacity of transition metal oxides as Li-ion battery cathodes is maximized when high oxidation states can be achieved, but these states are not stable, leading to irreversibility and failure…
Thumbnail for NMR insights into anti-perovskite solid electrolytes: A combination of experimental and computational 25Mg NMR studies
NMR insights into anti-perovskite solid electrolytes: A combination of experimental and computational 25Mg NMR studies
Magnesium-ion battery is a promising alternative to Lithium-ion batteries due to their potential for higher energy density. Solid electrolytes (SEs) play a critical role in the development of magnesium-ion batteries, as they offer increased safety and compatibility with metallic anodes…
Thumbnail for In-situ/Operando Se K-HERFD-XAS study of electrocatalytic reduction of carbon dioxide with transition metal diselenides
In-situ/Operando Se K-HERFD-XAS study of electrocatalytic reduction of carbon dioxide with transition metal diselenides
The electrocatalytic reduction of CO2 to energy-rich syngas, methanol, or even hydrocarbons offers an attractive route for converting greenhouse gas into value-added chemicals and storage of energy…