Seung-Chan Baek

A highly active and stable catalyst for carbon dioxide reforming of methane: Ni/Ce-ZrO2/θ-Al2O3

A novel catalyst, Ni/Ce-ZrO2/θ-Al2O3 has been designed and examined in carbon dioxide reforming of methane. It gives synthesis gas with CH4 conversion more than 97% at 800 °C and the activity was maintained during the reaction for longer than 40 h. The high stability of the catalyst is mainly ascribed to the beneficial precoating effect of Ce-ZrO2 resulting in the existence of stable NiOx species, a strong interaction between Ni and the support, and an abundance of mobile oxygen species in itself. From TPR results, it has been confirmed that NiOx formation is more favorable than NiO or NiAl2O4 formation, resulting in strong interaction between Ni and the support.

Kinetics modeling for the mixed reforming of methane over Ni-CeO2/MgAl2O4 catalyst

Abstract Kinetics model was developed for the mixed (steam and dry) reforming of methane, which is useful for the control of H 2 /CO ratio. The equilibrium constants of reaction rate were determined using the experimental equilibrium data at different reaction temperatures, while the forward reaction rate constants were estimated using the experimental data under non-equilibrium (high inert fraction and high space velocity) conditions. The comparison between calculated and experimental data clearly showed that the developed model described satisfactorily, and further analysis using the parametric sensitivity determined the wall temperature and CO 2 fraction in the feed gas as effective parameters for the manipulation of CH 4 conversion and H 2 /CO ratio of synthesis gas under the equilibrium condition. Meanwhile, the inert fraction, rather than the residence time, was selected as additional parameter under non-equilibrium condition.

The promotional effect of CO2 in ethylbenzene oxidation with MC-type catalytic system

Abstract The promotional effect of CO 2 in the liquid phase oxidation of ethylbenzene to acetophenone (AP) with the Co/Mn/Br (MC-type) catalyst system has been investigated. Significant enhancement of catalytic activity was found in the presence of CO 2 and thus selectivity toward acetophenone was increased as well. UV-visible investigations of the MC-type catalyst system in the oxidation of ethylbenzene reveal that Mn(III) is more easily formed in the presence of CO 2 ; such formation would be associated with the CO 2 promotional effect.