Catalysis Today 187 (2012) 77–87 Contents lists available at SciVerse ScienceDirect Catalysis Today jou rn al h om epage: www.elsevier.com/locate/cattod Methanol decomposition on electrospun zirconia nanofibers R. Ruiz-Rosas a , J. Bedia a , J.M. Rosas a , M. Lallave b , I.G. Loscertales c , J. Rodríguez-Mirasol a,∗ , T. Cordero a a Chemical Engineering Department, School of Industrial Engineering, University of Málaga, Campus de Teatinos s/n, 29071 Málaga, Spain b YFLOW-Sistemas y Desarrollo S.L., PTA, 29050 Málaga, Spain c Department of Mechanical Engineering and Fluid Mechanics, School of Industrial Engineering, University of Málaga, Campus de Teatinos s/n, 29071 Málaga, Spain a r t i c l e i n f o Article history: Received 8 August 2011 Received in revised form 3 October 2011 Accepted 13 October 2011 Available online 3 December 2011 This paper is dedicated to the Memory of our colleague and friend Prof. A. Barrero. Keywords: Methanol decomposition Zirconia Electrospinning Nanofibers Heterogeneous catalysis a b s t r a c t Electrospinning has been used for the preparation of PVP–zirconium acetate nanofibers. The obtained non-woven cloths have been calcined at different temperatures (200–1000 ◦ C) and used as heteroge- neous catalysts in the gas phase decomposition of methanol. The X-ray diffraction spectra of the zirconia nanofibers show the onset of a semicrystalline tetragonal structure for the fibers calcined at 400 ◦ C. Trans- formation from tetragonal to monoclinic zirconia starts at a calcination temperature between 600 and 800 ◦ C. SEM and TEM images of the zirconia nanofibers show fibers with a high aspect ratio and sizes as thin as 200 nm. The increase of the calcination temperature results in zirconia fiber catalysts with lower methanol steady state conversions, probably due to changes in the crystalline phase and crystal sinter- ing. The fibers calcined at 500 ◦ C yielded the highest methanol conversion and selectivities to dimethyl ether. In general trend, methanol dehydrates to dimethyl ether at the lower reaction temperatures and decomposes to hydrogen and carbon monoxide at the higher reaction temperatures. Deactivation of the catalyst is observed only at the highest reaction temperature, being probably related to deposition over the fiber surface of pyrolytic carbon from cracking reaction of dimethyl ether. © 2011 Elsevier B.V. All rights reserved. 1. Introduction Zirconia exhibits advantageous physical and chemical proper- ties such as excellent thermal and chemical stability, high strength and fracture toughness, low thermal conductivity, high corrosion resistance and both acidic and basic properties. These advan- tages make zirconia materials suitable for applications in structural materials, thermal barrier coatings, oxygen sensors, fuel cells, cat- alysts and catalytic supports and as a gate dielectric in metal oxide-semiconductor (MOS) devices [1,2]. Nanostructured materials such as nanofibers or nanowires show interesting physical and chemical properties, which make them promising materials for applications in semiconductor, energy stor- age, biomedicine or catalysis fields and play an important role in fundamental research as well as industrial application [3–6]. Pore diffusion resistance is significant in pellet shaped catalysts, while powdered catalysts, as was the practice in most laboratory-scale studies could cause problems of high pressure drop in industrial size reactors. Therefore, the use of novel forms of catalyst supports, as fiber catalysts, is a key point for many catalytic industrial pro- cesses. Fibers as catalyst supports are easy to handle, may be packed or constructed in the best form to fit the particular use and show ∗ Corresponding author. Tel.: +34 951952385. E-mail address: mirasol@uma.es (J. Rodríguez-Mirasol). very small resistance to diffusion and lower pressure drop [7]. In the technical literature, zirconia nanofibers or nanowires are obtained from porous anodic alumina oxide templates [8], sol-gel deposition procedures [9] or solution routes [10]. In contrast to these meth- ods, electrospinning is a simple and straightforward method that has been used to obtain carbon and polymer fibers in the submicro and nanoscale [11–14]. In the electrospinning process, a polymer solution held by its surface tension at the end of a capillary tube is subjected to an electric field. When the applied electric field reaches a critical value, the repulsive electrical forces overcome the surface tension forces. Eventually, a charged jet of the solution is ejected from the tip of the charged conical meniscus known as the Taylor cone and a rapid, unstable whipping of the jet occurs in the space between the capillary tip and collector which leads to evaporation of the solvent, leaving a polymer fiber behind [11]. Parameters such as viscosity, flow, concentration of electrospun solution or applied voltage control diameter and length of fibers [15,16]. The intensive use of biomass, especially of biomass waste, as a renewable source of energy and high added valued products could reduce significantly the dependency of the fossil fuels and decrease the carbon dioxide emissions [17]. The use of biofuels offers advan- tages over the fossil fuels in terms of (a) availability of renewable sources; (b) representing CO 2 cycle in combustion; (c) environmen- tally friendly; and (d) biodegradable and sustainable [18]. (Bio)methanol is used as source of a high amount of very valu- able products by means of different catalytic processes such as 0920-5861/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.cattod.2011.10.031