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Updated: Sep 21, 2025
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Multiscale Sampling of a Heterogeneous Water/Metal Catalyst Interface using Density Functional Theory and Force-Field Molecular Dynamics
Published on: April 12, 2019
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Multiple Surface Site Three-Dimensional Structure Determination of a Supported Molecular Catalyst.
Ribal Jabbour1, Marc Renom-Carrasco2, Ka Wing Chan3
1Université de Lyon, CNRS, ENS Lyon, Université Lyon 1, Centre de RMN de Lyon, UMR 5082, 5 rue de la Doua, 69100 Villeurbanne, France.
Journal of the American Chemical Society
|June 1, 2022
Summary
This study reveals the atomic structure of iridium-N-heterocyclic carbene catalysts on silica using advanced NMR techniques. It uncovers unexpected structural diversity, crucial for designing high-performance supported catalysts.
Area of Science:
- Catalysis
- Materials Science
- Surface Chemistry
Background:
- Characterizing supported molecular catalysts is difficult due to low active site density and complex surface chemistry.
- Understanding the atomic-scale structure of these catalysts is essential for optimizing their performance.
Purpose of the Study:
- To provide a complete atomic-scale description of iridium-N-heterocyclic carbene (Ir-NHC) sites on silica throughout synthesis.
- To develop and apply site-selective methods for characterizing complex supported catalyst systems.
Main Methods:
- Utilized isotope labeling with multinuclear dipolar recoupling DNP-enhanced NMR spectroscopy for 3D structure determination.
- Implemented site-selective experiments to probe organometallic group proximity to the support.
- Combined EXAFS spectroscopy, chemical analysis, and computational studies for structural interpretation.
Main Results:
- Determined the 3D structure of Ir-NHC sites and synthesis intermediates.
- Identified two distinct coordination geometries for the iridium sites.
- Revealed unexpected structural features, including a fragment with two NHC and two Cl ligands.
Conclusions:
- Demonstrated a novel methodology for elucidating individual surface structures in complex, multisite heterogeneous catalysts.
- Highlighted the significant structural diversity in functional materials prepared via surface chemistry.
- Provided essential knowledge for designing improved supported catalysts.
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