Abstract
The present work aims to explore the impact of the support (MxOy: Al2O3, TiO2, Fe2O3, CeO2, ZnO) on the CO2 hydrogenation activity of supported gold nanoparticles (Au/Mx0y) at atmospheric pressure. The textural, redox and surface properties of Au/MxOy catalysts were evaluated by various characterisation methods, namely N-2 adsorption-desorption at -196 degrees C, temperature-programmed reduction in H-2, high resolution transmission electron microscopy and X-ray photoelectron spectroscopy. The results revealed a strong influence of the support both on CO2 conversion and on products distribution. Gold nanoparticles supported on ZnO and CeO2 were highly selective towards methanol. TiO2- and Fe2O3-based samples demonstrated high CO2 conversion, leading, however, almost exclusively to CO and/or CH4. Au/Al2O3 was practically inactive in the investigated temperature range (200-350 degrees C). The following activity order, in terms of methanol formation rate, was obtained: Au/CeO2 > Au/ZnO > Au/Fe2O3 > Au/TiO2 > Au/Al2O3. Au/CeO2 exhibited a methanol formation rate of 4.1 x 10(-6) mol s(-1) gAu(-1) at 250 degrees C, which is amongst the highest reported at ambient pressure, in spite of the chemical inertness of bare ceria. In view of the characterisation results, the superiority of the Au/CeO2 sample could be mainly ascribed to a synergistic effect linked to the Au-ceria interactions.
| Original language | English |
|---|---|
| Pages (from-to) | 247-256 |
| Number of pages | 10 |
| Journal | Journal of CO2 Utilization |
| Volume | 19 |
| DOIs | |
| Publication status | Published - May-2017 |
| Externally published | Yes |
Keywords
- CO2 hydrogenation
- Au nanoparticles
- Methanol synthesis
- Metal-support interactions
- GAS SHIFT REACTION
- CO OXIDATION
- AU/FE2O3 CATALYSTS
- METHANOL SYNTHESIS
- GOLD CATALYSTS
- ATMOSPHERIC-PRESSURE
- OXIDE CATALYSTS
- METAL-OXIDE
- OXYGEN
- DEACTIVATION