Mesostructured Ni-doped ceria as an efficient catalyst for styrene synthesis by oxidative dehydrogenation of ethylbenzene

Mesostructured doped Ce(1-x)M(x)O catalysts (M = Al, Sn, Zr, Mn, and Ni) with large surface area prepared via template-assisted precipitation method have been tested for the oxidative dehydrogenation (ODH) of ethylbenzene (EB) to styrene. Several techniques including N(2) desorption-adsorption, X-ray diffraction, H(2)-temperature programmed reduction (H(2)-TPR), total oxygen storage capacity (OSC), and X-ray photoelectron spectroscopy (XPS) were applied to characterize the physicochemical properties of the as-synthesized materials. Of the Ce(1-x)M(x)O catalysts tested, the CeNiO composite containing 10 mol% Ni demonstrates the highest ST yield of 55% with long-term stability for ODH of EB under 450 degrees C. By analysis of H(2)-TPR and total OSC characterization profiles, the superior performance of Ce(0.90)Ni(0.10)O catalyst can be attributed to the dramatic improvement in oxygen mobility and storage capacity of the ceria materials, resulting from the introduction of Ni species into ceria cubic structure and hence a further shrinkage of ceria lattice. A catalytic mechanism via a simple surface redox cycle has been tentatively proposed based on the XPS results. (C) 2011 Elsevier B.V. All rights reserved.