Akademik Veri Yönetim Sistemi
Canadian Journal of Chemical Engineering, 2026 (SCI-Expanded, Scopus)
This study aimed to investigate the effects of the addition of CeO2 to the chromium-based catalyst on the activity and selectivity of the isobutane dehydrogenation. MCM-41 supported catalysts without Ce and with Ce/Cr mass ratios of 1 and 5 were first prepared hydrothermally (Cr:10%, by mass). As the Ce/Cr ratio increased, the formation of inactive α-Cr2O3 decreased and almost disappeared when the Ce/Cr ratio was 5; thus, it was decided to use this ratio in further catalyst preparation. Then, catalysts with and without Ce were prepared by the impregnation method. X-ray diffraction (XRD) and scanning electron microscopy (SEM)/energy dispersive spectroscopy (EDS) analyses showed that CeO2 distribution was better in the hydrothermally prepared catalyst. IR analyses of pyridine adsorbed catalysts showed that the number of Bronsted acid centres increased when CeO2 was not well dispersed in the catalyst structure prepared by the impregnation method. Since high Bronsted acidity caused more α-hydrogen displacement, the formation of deep oxidation product COx increased and lower isobutene selectivities were observed. When Ce was added to the chromium-based catalyst, the total number of acid centres decreased by approximately 50% and the oxygen capacity increased approximately twofold. The decrease in acidity with the addition of Ce also reduced the formation of deep oxidation product COx. Ce addition prevented the rapid decrease in conversion and selectivity in the CrOx catalyst synthesized hydrothermally. Isobutane conversion and isobutene selectivity were maintained at approximately 85% during 2 h reaction period. This was explained by the fact that CeO2 successfully transferred the oxygen required for the reaction to the neighbouring.