Mossbauer spectroscopic studies of Fe2O3-K2O-based catalysts for ethylbenzene dehydrogenation
- 化学化工－已发表论文 
Fe2O3-K2O Catalysts with different content of K2O and calcined at different temperature Mere characterized by using Mossbauer spectroscopy. It was found from the experiments that only a sextuplet assignable to Fe3+ of alpha-Fe2O3 could be detected while the K2O content in these catalysts were lower than 5% and the calcination temperature was below 900 degrees C; and complex spectra, which could be fitted with several sextuplets of trivalent irons present in alpha-Fe2O3, KFeO2, K1+xFe11O17 and alpha-FeOOH, and a doublet of Fe3+ in gamma-FeOOH, would be observed if the K2O content were 10% similar to 27% and the calcination temperature were 800 similar to 900 degrees C. The gamma-FeOOH, as a hydrous iron oxide, was the decomposition product of KFeO2 which was strong hydroscopic by absorbing moisture from the atmosphere. The results also suggested that Mossbauer spectroscopy was a better mean than XRD for the characterizations of Fe2O3-K2O catalysts, by which, alpha-FeOOH, gamma-FeOOH and alpha-Fe2O3 in amorphous or crystallite forms ( unable to be found by XRD) could be detected. It was also shown from the Mossbauer spectroscopy and a TPR studies that potassium could retard the reduction of Fe(III) to Fe(II) in the Fe2O3-K2O catalysts.