CHEMICAL ENGINEERING TRANSACTIONS VOL. 43, 2015 A publication of The Italian Association of Chemical Engineering Online at www.aidic.it/cet Chief Editors: Sauro Pierucci, Jiří J. Klemeš Copyright © 2015, AIDIC Servizi S.r.l., I SBN 978-88-95608-34-1; I SSN 2283-9216 Water Gas Shift Reaction on Copper Catalysts Supported on Alumina and Carbon Nanofibers Natália M. B. Oliveira* a , Gustavo P. Valença a , Ricardo Vieira b a School of Chemical Engineering, State University of Campinas, Campinas (SP), Brazil b Associated Laboratory of Combustion and Propulsion, National Institute for Space Research, Cachoeira Paulista (SP), Brazil nataliaoliveira.eq@gmail.com The water gas shift (WGS) reaction is widely used in the production of hydrogen, by the conversion of carbon monoxide into CO 2 and of water into H 2 . In the present work, copper catalysts supported on alumina or carbon nanofibers (CNF) were used to study the WGS reaction. The catalysts were prepared by impregnating copper nitrate in the supports, with a nominal mass metallic content of 5%. The solids were dried, calcined and characterized by X-Ray Diffraction (XRD), nitrogen adsorption, nitrous oxide chemisorption and Inductively Coupled Plasma Optical Emission Spectrometry (ICP OES). After calcination, the catalysts were loaded into the reactor, reduced and then tested in the WGS reaction at medium temperatures (398 – 573 K). The gases from reactor were analyzed online by Gas Chromatography (GC). The products were CO 2 , H 2 and, probably, small amounts of coke. The CO partial pressure varied between 4.6 and 6.6 kPa, and the water partial pressure varied between 20.0 and 47.4 kPa. Among the catalysts tested, 5% Cu/Al 2 O ଷ was the most active under all conditions used in this work, due to the high dispersion of the metal particles on the support. The most favorable reaction conditions for this catalyst were p H2O 0 = 38.6 kPa and p CO 0 = 5.3 kPa (H2O:CO molar ratio of 7.3), for all reaction temperatures used in this work. Cu/CNF had low CO conversions, due to the support hydrophobicity. In case of this catalyst, the most favorable conditions were p H2O 0 = 20.0 kPa and p CO 0 = 6.6 kPa, corresponding to a H 2 O:CO molar ratio of 3.1. The apparent activation energy calculated for the WGS reaction was 86.1 kJ mol -1 for 5% Cu/Al 2 O ଷ and 69.8 kJ mol -1 for 5% Cu/CNF. For Cu/CNF a co-operative redox reaction mechanism was proposed, and apparent reaction orders were 0.64 in relation to CO and approximately zero in relation to water. 1. Introduction The water gas shift (WGS) reaction, ܥ (௚) + ܪ ଶ  (௚) ܥ⇄ ଶ (௚) + ܪ ଶ (௚) , is an important industrial reaction for the production of hydrogen. Hydrogen is used in fuel cells and in important processes, such as synthesis of ammonia and refining of fossil fuels by hydrocracking (Ratnasamy and Wagner, 2009; Palma et al., 2014). In addition, there is an increasing economic interest in the use of hydrogen as a transportable fuel, hydrogen being a promising substitute for gasoline and diesel (Chen et al., 2008). Depending on the hydrogen application, the reactant gas compositions and the adopted reaction conditions may vary. According to Ratnasamy and Wagner (2009), the main problem is when the reaction products are present in reactor feed, since they are rate limiting. The increasing economic interest in production of hydrogen makes the study of the WGS reaction highly attractive. The aim is to develop catalysts which are able to achieve conversions of carbon monoxide higher than those obtained on commercial catalysts such as Cu/ZnO/Al 2 O ଷ (Ratnasamy and Wagner, 2009). Although the reaction rate per unit volume is high on this catalyst, the stability under high temperature is low. In addition, industrial catalysts used in the WGS reaction have many weaknesses (Gunawardana et al., 2009). For example, the global system kinetics is very slow at temperatures at which chemical equilibrium is favorable, requiring a high mass of catalyst, that in turn results in long in situ reduction prior to reaction (Palma DOI: 10.3303/CET1543156 Please cite this article as: Oliveira N., Valenca G., Vieira R., 2015, Water gas shift reaction on copper catalysts supported on alumina and carbon nanofibers, Chemical Engineering Transactions, 43, 931-936 DOI: 10.3303/CET1543156 931