In this work, Pt nanoparticles were loaded on SiO2, TiO2-thin-film-modified SiO2 (TiO2-SiO2), or ZrO2-thin-film-modified SiO2 (ZrO2-SiO2) particles and the composites were investigated for sequential adsorption and desorption/catalytic oxidation of benzene. The SiO2 was prepared via sol–gel method, while TiO2-SiO2 and ZrO2-SiO2 were synthesized via atomic layer deposition (ALD) thin film coating of TiO2 or ZrO2 on SiO2 particles substrate. In the sequential capture-reaction tests, the materials were first exposed to ca. 500 ppmv benzene gas at 25 °C and 1 atm until 5% breakthrough was attained, followed by tandem desorption and catalytic oxidation while raising bed temperature to 200 °C. The benzene vapor adsorption isotherms followed type-IV isotherm classification, revealing a combination of monolayer, multilayer and capillary condensation adsorption mechanisms in sequence. The xPt/ZrO2-SiO2 materials exhibited superior capture-conversion capabilities relative to their xPt/TiO2-SiO2. In particular, 3Pt/ZrO2-SiO2, prepared with 3 cycles of Pt ALD, exhibited the maximum in-situ conversion at ∼ 100% and turnover frequency of 17.1 mmolC6H6/molPt/s with a dynamic adsorption capacity of 0.45 mmol/g, indicating synergistic effects of Pt nanoparticles and ZrO2 in the ALD-based dual-function materials.
B. O. Adebayo et al., "Atomic Layer Deposited Pt/TiO2-SiO2 and Pt/ZrO2-SiO2 for Sequential Adsorption and Oxidation of VOCs," Chemical Engineering Journal, vol. 444, article no. 136603, Elsevier, Sep 2022.
The definitive version is available at https://doi.org/10.1016/j.cej.2022.136603
Chemical and Biochemical Engineering
Keywords and Phrases
Adsorption; ALD; Catalysis; Mixed-metal oxide; Oxidation; Pt; VOC
International Standard Serial Number (ISSN)
Article - Journal
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15 Sep 2022