par Lambeets, Sten 
;Barroo, Cédric ;Kruse, Norbert ;Visart de Bocarmé, Thierry
Référence International Conference on Atom Probe Tomography & Microscopy 2014 – APT&M 2014 (2014-08-31->09-05: Stuttgart, Allemagne)
Publication Non publié, 2014-08-31
;Barroo, Cédric ;Kruse, Norbert ;Visart de Bocarmé, Thierry Référence International Conference on Atom Probe Tomography & Microscopy 2014 – APT&M 2014 (2014-08-31->09-05: Stuttgart, Allemagne)
Publication Non publié, 2014-08-31
Communication à un colloque
| Résumé : | Turning CO2 gas into useful products is a welcome means to address the issue of global warming. For instance, heterogeneous catalysis may be used to produce methanol by CO2 hydrogenation. To improve the efficiency of respective catalysts, a sound understanding of the reaction processes at the molecular level is required. This paper reports the study of CO2 adsorption as well as CO2+H2 reaction on nanosized rhodium field emitter crystals. The systems have been studied using field emission techniques.Rhodium samples are characterized by FIM, whereas CO2 adsorption and dissociation are followed by FEM. Modifications of the local surface composition are translated to variations of brightness through the work function and eventually brightness analysis is used to monitor the reaction during the ongoing process. The introduction of pure CO2 during imaging causes a brightness decrease due to dissociative adsorption of CO2(g). Upon increase the hydrogen pressure, reactive phenomena are observed from 650K to 700K, as indicated by increasing brightness. These results are compared to literature data which allow the proposal of a scenario explaining these observations and corresponding to the Reverse-Water-Gas-Shift reaction (CO2+H2→CO+H2O). These assumptions are in line with a direct local chemical analysis using a 1D-atom probe under environmental conditions. |
