Structure-activity relationships in metal organic framework derived mesoporous nitrogen-doped carbon containing atomically dispersed iron sites for CO&lt;sub&gt;2&lt;/sub&gt; electrochemical reduction

Sun, X.; Wang, R.; Ould-Chikh, Samy; Osadchii, D.; Li, G.; Aguilar, Antonio; Hazemann, Jean louis; Kapteijn, F.; Gascon, Jorge

doi:10.1016/j.jcat.2019.09.013

Structure-activity relationships in metal organic framework derived mesoporous nitrogen-doped carbon containing atomically dispersed iron sites for CO₂ electrochemical reduction

Title

Structure-activity relationships in metal organic framework derived mesoporous nitrogen-doped carbon containing atomically dispersed iron sites for CO₂ electrochemical reduction

Author

Sun, X. (TU Delft ChemE/Catalysis Engineering)
Wang, R. (TU Delft ChemE/Catalysis Engineering)
Ould-Chikh, Samy (King Abdullah University of Science and Technology)
Osadchii, D. (TU Delft ChemE/Catalysis Engineering)
Li, G. (TU Delft ChemE/Inorganic Systems Engineering; TU Delft ChemE/Catalysis Engineering)
Aguilar, Antonio (Université Grenoble Alpes)
Hazemann, Jean louis (Université Grenoble Alpes)
Kapteijn, F. (TU Delft ChemE/Catalysis Engineering)
Gascon, Jorge (TU Delft ChemE/Catalysis Engineering; King Abdullah University of Science and Technology)

Date

2019

Abstract

Mesoporous nitrogen-doped carbon nanoparticles with atomically dispersed iron sites (named mesoNC-Fe) are synthesized via high-temperature pyrolysis of an Fe containing ZIF-8 MOF. Hydrolysis of tetramethyl orthosilicate (TMOS) in the MOF framework prior to pyrolysis plays an essential role in maintaining a high surface area during the formation of the carbon structure, impeding the formation of iron (oxide) nanoparticles. To gain inside on the nature of the resulting atomically dispersed Fe moieties, HERFD-XANES, EXAFS and valence-to-core X-ray emission spectroscopies have been used. The experimental spectra (both XAS and XES) combined with theoretical calculations suggest that iron has a coordination sphere including a porphyrinic environment and OH/H₂O moieties responsible for the high activity in CO₂ electroreduction. DFT calculations demonstrate that CO formation is favored in these structures because the free energy barriers of *COOH formation are decreased and the adsorption of *H is impeded. The combination of such a unique coordination environment with a high surface area in the carbon structure of mesoNC-Fe makes more active sites accessible during catalysis and promotes CO₂ electroreduction.

Subject

Atomically dispersed sites
CO
Electroreduction
Iron

To reference this document use:

http://resolver.tudelft.nl/uuid:9e5de706-0275-46b3-b074-aa291b9247d7

DOI

https://doi.org/10.1016/j.jcat.2019.09.013

Embargo date

2021-09-25

ISSN

0021-9517

Source

Journal of Catalysis, 378, 320-330