Related Experiment Video
Updated: Jan 7, 2026
04:51
Author Spotlight: Functionalizing Metal-Organic Frameworks: Advancements, Challenges, and the Power of Post-Synthetic Ligand Exchange
Published on: June 23, 2023
4.1K
Modulator Control of Cation Distribution in Mixed-Metal UiO-66(Zr,Ce) Metal-Organic Frameworks
Baiwen Zhao1, Martin Hutereau2, Marc Walker3
1Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, U.K.
Chemistry of Materials : a Publication of the American Chemical Society
|December 31, 2025
Summary
Modulators like benzoic acid control metal distribution in bimetallic UiO-66-(Ce/Zr) metal-organic frameworks (MOFs), enhancing cerium incorporation and catalytic activity in oxidation reactions.
Area of Science:
- Materials Science
- Catalysis
- Nanotechnology
Background:
- Bimetallic metal-organic frameworks (MOFs) like UiO-66-(Ce/Zr) are promising for catalysis.
- Controlling cation distribution within MOF clusters is crucial for tuning properties.
- The synthesis process, particularly modulator choice, influences MOF structure and performance.
Purpose of the Study:
- To investigate how different modulators affect cation distribution and redox activity in UiO-66-(Ce/Zr) MOFs.
- To correlate the local structure of Ce-Zr clusters with catalytic performance in benzyl alcohol oxidation.
- To understand the mechanism of cerium incorporation during MOF synthesis.
Main Methods:
- Extended X-ray absorption spectroscopy (EXAFS) at Ce and Zr K-edges.
- In situ Fourier-transform infrared (FTIR) spectroscopy.
- Density functional theory (DFT) calculations.
- Ce K-edge EXAFS and Ce LIII-edge X-ray absorption near edge structure (XANES) analysis of reaction solutions.
- Microwave-assisted benzyl alcohol oxidation reaction.
Main Results:
- Benzoic acid modulation favors the formation of cis-Ce2Zr4 clusters with higher Ce incorporation (33%) compared to formic acid (17% CeZr5 clusters).
- Ce(III) in solution limits Ce(IV) uptake, but benzoic acid mitigates this effect, enhancing overall Ce incorporation.
- The cis-Ce2Zr4 clusters exhibit higher redox activity and catalytic efficiency in benzyl alcohol oxidation than CeZr5 clusters.
- Local metal distribution significantly impacts catalytic activity, with cis-Ce2Zr4 clusters showing superior performance due to easier oxide ion removal.
Conclusions:
- The choice of modulator is a key factor in controlling local cation distribution within UiO-66-(Ce/Zr) MOF clusters.
- Fine-tuning the metal cluster structure through modulator selection offers a subtle yet effective strategy to enhance catalytic properties.
- Understanding and controlling cation distribution is essential for designing advanced MOF catalysts for specific applications.
Related Concept Videos
02:51Metal-Ligand Bonds
23.8K
The hemoglobin in the blood, the chlorophyll in green plants, vitamin B-12, and the catalyst used in the manufacture of polyethylene all contain coordination compounds. Ions of the metals, especially the transition metals, are likely to form complexes.
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
23.8K
02:58Crystal Field Theory - Octahedral Complexes
30.4K
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
30.4K
02:42Ionic Crystal Structures
16.7K
Ionic crystals consist of two or more different kinds of ions that usually have different sizes. The packing of these ions into a crystal structure is more complex than the packing of metal atoms that are the same size.
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
16.7K