Applied Catalysis A: General 199 (2000) 83–92 Recovery of ethene-selective FeO x /Al 2 O 3 ethanol dehydration catalyst from industrial chemical wastes Ezzat A. El-Katatny a , Samih A. Halawy b , Mohamed A. Mohamed c , Mohamed I. Zaki d,∗ a Aluminium Company of Egypt, Nag-Hammady, Egypt b Chemistry Department, College of Education, King Faisal University, P.O. Box 1759, Al-Hofuf 31982, Eastern Province, Saudi Arabia c Chemistry Department, Faculty of Science, Qena, South Valley University, Qena 83511, Egypt d Chemistry Department, Faculty of Science, Kuwait University, P.O. Box 5969, 13060 Safat, Kuwait Received 15 September 1999; received in revised form 26 November 1999; accepted 30 November 1999 Abstract Boehmite, -AlO(OH), recovered from aluminium dross tailings (ADT) and steel-pickling chemical waste (SPW) were used to prepare 1–10 wt.% FeO x /Al 2 O 3 catalysts. Surface and bulk properties of the catalysts were characterized by nitrogen sorptometry, thermogravimetry (TG) of adsorbed pyridine, X-ray photoelectron spectroscopy and X-ray powder diffractom- etry. The results have shown the catalysts to consist of highly dispersed -Fe 2 O 3 particles on high-surface area -Al 2 O 3 , but cannot exclude the coexistence of monolayer species of Fe(II)–O and/or Fe(III)–O, as well as Fe(III) incursions into the sup- port bulk structure. Activity tests of the catalysts towards ethanol dehydration (at 140–250 ◦ C) in the gas phase, have revealed that increasing amounts of supported FeO x species could turn -Al 2 O 3 from being diethyl ether selective to ethene selective, without changing its originally high dehydration activity towards the alcohol. Consequent modifications of the surface acid site density have been correlated to observed changes in the alcohol dehydration rate. Hence, the switching of the catalyst selectivity to ethene formation has been suggested to follow suppression (or elimination) of bi-molecular reaction mechanism necessary for ether formation due to Fe(III) incursion into the support, and/or ether decomposition on Fe 2 O 3 particles. © 2000 Elsevier Science B.V. All rights reserved. Keywords: Aluminium dross tailings; Steel-pickling chemical waste; Ethanol dehydration activity; FeO x /Al 2 O 3 catalysts; Catalyst characterization; DTA; XPS; XRD 1. Introduction Industrial chemical wastes, if inadequately disposed or improperly utilized, represent a real challenge to en- vironmentalists. Aluminium dross tailings (ADT) and steel-pickling chemical waste (SPW) are two obvious challenging examples, particularly to environmental- ists in developing countries. In Egypt, for example, ∗ Corresponding author. Fax: +965-484-6946. E-mail address: zaki@kuc01.kuniv.edu.kw (M.I. Zaki) these materials are produced in large quantities (∼1000–2000 tons per year), and to date, are neither properly utilized, nor adequately disposed. Research efforts exerted in these, and other, laboratories have designed practical procedures for the recovery of use- ful materials from ADT and SPW. Accordingly, ther- mochemical methods have been devised to derive high area -Al 2 O 3 from ADT [1,2] and quality red iron ox- ide pigmentary powders (-Fe 2 O 3 ) from SPW [3–6]. In line with these research endeavours, the present paper communicates a further attempt at utilizing 0926-860X/00/$ – see front matter ©2000 Elsevier Science B.V. All rights reserved. PII:S0926-860X(99)00539-6