Study of the Photothermal Catalytic Mechanism of CO<sub>2</sub> Reduction to CH<sub>4</sub> by Ruthenium Nanoparticles Supported on Titanate Nanotubes
The Sabatier reaction could be a key tool for the future of the renewable energy field due to the potential of this reaction to produce either fuels or to stabilize H<sub>2</sub> in the form of stable chemicals. For this purpose, a new composite made of ruthenium oxide nanoparticles (NPs...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-11-01
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| Series: | Nanomaterials |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2079-4991/10/11/2212 |
| Summary: | The Sabatier reaction could be a key tool for the future of the renewable energy field due to the potential of this reaction to produce either fuels or to stabilize H<sub>2</sub> in the form of stable chemicals. For this purpose, a new composite made of ruthenium oxide nanoparticles (NPs) deposited on titanate nanotubes (TiNTs) was tested. Titanate nanotubes are a robust semiconductor with a one-dimensional (1D) morphology that results in a high contact area making this material suitable for photocatalysis. Small ruthenium nanoparticles (1.5 nm) were deposited on TiNTs at different ratios by Na<sup>+</sup>-to-Ru<sup>3+</sup> ion exchanges followed by calcination. These samples were tested varying light power and temperature conditions to study the reaction mechanism during catalysis. Methanation of CO<sub>2</sub> catalyzed by Ru/TiNT composite exhibit photonic and thermic contributions, and their ratios vary with temperature and light intensity. The synthesized composite achieved a production rate of 12.4 mmol CH<sub>4</sub>·g<sub>cat</sub><sup>−1</sup>·h<sup>−1</sup> equivalent to 110.7 mmol of CH<sub>4</sub>·g<sub>Ru</sub><sup>−1</sup>·h<sup>−1</sup> under 150 mW/cm<sup>2</sup> simulated sunlight irradiation at 210 °C. It was found that photo-response derives either from Ru nanoparticle excitation in the visible (VIS) and near-infrared (NIR) region (photothermal and plasmon excitation mechanism) or from TiNT excitation in the ultraviolet (UV) region leading to electron–hole separation and photoinduced electron transfer. |
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| ISSN: | 2079-4991 |