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Updated: Sep 14, 2025
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Synthesis and Performance Characterizations of Transition Metal Single Atom Catalyst for Electrochemical CO2 Reduction
Published on: April 10, 2018
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Metal-Oxide Interface Sites Created Using Atomic Layer Deposition and Tested for CO Oxidation
Wang Ke1, Ilkeun Lee1, Francisco Zaera1
1Department of Chemistry and UCR Center for Catalysis, University of California, Riverside, California 92521, United States.
ACS Catalysis
|July 24, 2025
Summary
The order of depositing platinum (Pt) and titanium dioxide (TiO2) on SBA-15 significantly impacts catalyst performance. Depositing TiO2 first, followed by Pt, optimizes catalytic activity by creating ideal Pt/TiO2 interface sites for reactions.
Area of Science:
- Materials Science
- Catalysis
- Nanotechnology
Background:
- High-surface-area catalysts are crucial for various chemical reactions.
- Controlling the interface between metal nanoparticles and support materials is key to optimizing catalyst performance.
- Atomic Layer Deposition (ALD) offers precise control over thin film deposition at the nanoscale.
Purpose of the Study:
- To systematically characterize the performance of Pt/TiO2 catalysts supported on SBA-15.
- To investigate the influence of the deposition order (TiO2 first vs. Pt first) on catalyst properties and activity.
- To elucidate the role of Pt/TiO2 interface sites in catalytic mechanisms.
Main Methods:
- Atomic Layer Deposition (ALD) for creating TiO2 thin films on SBA-15.
- In situ infrared absorption spectroscopy (IR) for characterizing adsorbed CO species.
- Electron microscopy for analyzing catalyst morphology.
- Adsorption-desorption isothermal measurements for surface area analysis.
Main Results:
- TiO2 films evenly distributed within SBA-15 mesopores with controllable submonolayer thickness.
- Deposition order significantly altered catalyst properties and Pt nanoparticle characteristics.
- Pt deposited on TiO2/SBA-15 resulted in smaller NPs and lower Pt coordination.
- TiO2 deposited on Pt/SBA-15 led to partial Pt surface blockage and altered CO binding at interface sites.
- Optimal catalytic activity achieved with TiO2 deposited first, at approximately half-monolayer coverage (≥2 ALD cycles).
Conclusions:
- The sequence of ALD for TiO2 and Pt deposition critically influences the resulting catalyst's structure-property relationships.
- Pt/TiO2 interface sites play a vital role in the catalytic reaction mechanism, involving CO adsorption and migration.
- Tuning the density of these interface sites by controlling TiO2 coverage is essential for maximizing catalytic efficiency.
