The influence of dopants on the catalytic activity of hematite in the ethylbenzene dehydrogenation

Abstract

The effect of neodymium, lanthanum, aluminum and zirconium on the textural and catalytic properties of hematite was studied in this work, which aimed to develop catalysts to ethylbenzene dehydrogenation, in the presence of steam, the main commercial route to obtain styrene. Hematite and magnetite were found in fresh and spent catalysts, respectively. All dopants increased the specific surface area of the fresh and spent catalysts and made them more resistant against reduction, but only aluminum avoided sintering during reaction. The dopants increased the catalytic activity per area of hematite, except aluminumwhich acted only as a textural promoter. The selectivity was decreased due to zirconium and lanthanum while the other dopants did not change this parameter. The neodymiumcontaining catalyst showed high levels of activity and selectivity and was able to work up to 530 8C, without deactivation, being the most promising with regard to styrene production.