A new one-dimensional tungsten carbide nanostructured material Nicolas Keller ⁎ , Barbara Pietruszka, Valérie Keller Laboratoire des Matériaux, Surfaces et Procédés pour la Catalyse, ECPM, Université Louis Pasteur, UMR 7515 CNRS, and ELCASS (European Laboratory for Catalysis and Surface Science), 25 rue Becquerel, BP 08, 67087 Strasbourg Cedex 2, France Received 1 March 2005; accepted 6 December 2005 Available online 27 December 2005 Abstract A new medium specific surface area one-dimensional tungsten carbide nanostructure was obtained by the Shape Memory Synthesis method, in which the macrostructural features of a carbonaceous 1D-preformed template were maintained during the carburization of tungsten oxide and determined the resulting carbide morphology. © 2005 Elsevier B.V. All rights reserved. Keywords: Carbon nanotubes; Catalysts; Nanomaterials; Tungsten carbide; Shape memory materials 1. Introduction Transition metal carbides (TMC), especially molybdenum and tungsten carbides, received a great interest since their catalytic properties, similar to Pt-like noble metals, were discovered at the beginning of the 70s [1–3]. The exciting possibility to substitute scarce and expensive noble metals with cheaper materials has led numerous groups worldwide to become deeply involved in this area. Their chemical flexibility renders them highly interesting in catalysis, since their surface and catalytic properties can be easily modified by mild oxidative post-synthesis treatments, leading to different active phases at their surface [4–8]. The chemistry of TMC has been extensively reviewed by Oyama [9], who described synthesis methods for obtaining medium/high surface area carbides, which usually require complex monitoring during the carburization period and often suffer from the pollution of the carbide surface by polymeric carbon, generally coming from the decomposition of the carbon- containing reactive mixture. In parallel to one-dimensional carbon nanostructures, for which the catalysis field seems to be promising due to their unusual behavior as catalyst supports for gas and liquid phase heterogeneous catalytic reactions, or even directly as catalysts, an increasing interest has also been devoted to new non- carbonaceous one-dimensional nanomaterials [10–13]. One- dimensional nanostructures such as carbon nanofibers/nano- tubes and β-SiC nanotubes have displayed interesting and promising behaviors in catalysis compared to their corresponding grain-sized materials. Amongst several possible explanations are (i) specific active phase-support interactions, (ii) the high external surface area with no microporous content, leading to a significant decrease in the mass transfer limitations, or (iii) confinement effects either for molecules or for the chemistry performed inside the nanotubes, provided by the surrounding tubular structure. These ideas have been advanced and summarized in recent reviews and articles [14–16]. The synthesis of TMC grains with 20–50 m 2 /g medium surface area has been reported according to the Shape Memory Synthesis (SMS) developed some years ago by Ledoux [17]. This method led to carbides with a surface free of carbon deposit, when compared to thermo-programmed carburization methods based on hydrocarbon decomposition. Its main concept is that an oxidic vapor or liquid of a metal or metalloid reacts with a carbon preform, whose macrostructural features determine the resulting carbide morphology. In order to bridge the macro- to nanoscale gap, multi-walled carbon nanotubes (CNTs) were chosen as the appropriate carbon precursor instead of activated charcoal grains in the SMS method. The aim of this article is to report on the synthesis of a new medium specific surface area one-dimensional tungsten carbide nanostructure for further use as catalyst, which could combine the intrinsic and Materials Letters 60 (2006) 1774 – 1777 www.elsevier.com/locate/matlet ⁎ Corresponding author. Tel.: +33 3 90 24 28 11; fax: +33 3 90 24 27 61. E-mail address: nkeller@chimie.u-strasbg.fr (N. Keller). 0167-577X/$ - see front matter © 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.matlet.2005.12.017