Alkali-ion promoted iron oxide was used as a catalyst for the non-oxidative dehydrogenation of ethylbenzene to styrene. Catalytic performance studies showed high activity, with selectivity ≈93% and conversion ≈49%. The fresh and used catalysts were characterised by various physicochemical techniques like scanning electron microscopy, x-ray diffraction and Mössbauer spectroscopy. X-ray and Mössbauer data clearly show the presence of α-Fe₂O₃ and Fe₃O₄ in the used catalysts and α-Fe₂O₃ in the fresh catalyst, the phases being identified from their standardd values and hyperfine interaction parameters.

Surface chemistry and structural changes of a potassia promoted, chromia stabilised iron oxide catalyst were examined before and after the non oxidative dehydrogenation of ethylbenzene to styrene using x-ray photoelectron spectroscopy (xps).

xps binding energies of the Fe(2p, 3s, 3p, 3d), K(2p, 3s, 3p), Cr(2p, 3s, 3p) and O(1s) levels along with characteristic shifts in the binding energies, spin-orbit splittings and satellite, multiplet splittings help in identifying surface active species such as Fe₂O₃, Fe₃O₄, FeOOH at the surface of fresh and used catalysts.