| Autor: |
Luciano, Atzori, Elisabetta, Rombi, Daniela, Meloni, Roberto, Monaci, Maria Franca, Sini, Maria Giorgia, Cutrufello |
| Rok vydání: |
2019 |
| Zdroj: |
Journal of nanoscience and nanotechnology. 19(6) |
| ISSN: |
1533-4880 |
| Popis: |
NiO-CeO₂-ZrO₂ mixed oxides, with Ni/(Ce + Zr) = 1 mol/mol and different Ce/Zr molar ratios, were prepared by the soft-template method. The chemical composition, texture, structure, and redox features of the synthesized systems were investigated by different techniques. All samples were nanocrystalline (NiO nanocrystal average size 4 nm) and had high surface area and quite an ordered mesoporous system. The catalytic performances in the CO₂ conversion into methane were studied at atmospheric pressure, 300 °C, and stoichiometric H₂/CO₂ molar ratio. Prior to reaction the catalysts were submitted to a mild reduction pretreatment (H₂ at 400 °C for 1 h). XRD analysis of the samples after pretreatment showed the presence of small Ni crystals (4-7 nm) on all the samples as well as of some unreduced NiO nanocrystals on the systems with high Zr content, in accordance with H₂-TPR experiments, which indicated that NiO reduction is promoted by CeO₂ but hindered by ZrO₂. The catalytic tests were performed at two different space velocities (72000 and 900000 cm³ h |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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