Oxidative Dehydrogenation Properties of Novel Nanostructured Polyoxovanadate Based Materials M. Ishaque Khan • Kadir Aydemir • M. Rafiq H. Siddiqui • Abdulrahman A. Alwarthan • Christopher L. Marshall Received: 14 June 2010 / Accepted: 7 January 2011 / Published online: 18 January 2011 Ó Springer Science+Business Media, LLC 2011 Abstract A comparative study of the catalytic oxidative dehydrogenation of propane by a novel polyoxovanadate based open-framework material (Co-POV)—[Co 3 V 18 O 42 (H 2 O) 12 (XO 4 )]Á24H 2 O (X = V, S), which is composed of nanometer size vanadium oxide clusters interlinked by cobalt oxide {–O–Co–O–} motifs, showed that Co-POV has superior catalytic property as compared to its individual metal oxide constituents, vanadium oxide and cobalt oxide, and their mixture, with high propylene selectivity. Keywords Oxidative dehydrogenation Á Catalysis Á Propylene Á Framework materials Á Polyoxovanadates Á X-ray absorption spectroscopy Á XANES 1 Introduction Propylene is an important intermediate for industrial pro- duction of acrylonitrile, polypropylene, propylene oxide, isopropanol, epichlorohydrin and cumine [1]. Global demand for propylene is expected to grow with an average rate of 5% while supply capacity will only grow with a rate of 4.5% [2]. The industrial propylene production routes such as steam cracking, fluid catalytic cracking and selective dehydrogenation suffer from low selectivity to desired product (resulting into undesired by-products) and coke formation. Oxidative dehydrogenation (ODH) of propane into propylene is an important alternative to these methods for industrial scale preparation of propylene. ODH of propane does not lead to the formation of coke and undesired lower molecular weight by-products. In most cases water and CO x gases are the only observed by- products [3–12]. Moreover, ODH of propane reaction is exothermic and propylene can be produced at relatively low temperature by this method. Vanadium oxide based catalysts [13–16] and molybde- num oxide based catalysts [17–20] have been studied for the ODH of propane. Vanadium oxide based catalysts are of particular interest because of the unique properties of vanadium. Vanadium exhibits rich redox chemistry and variable oxidation states (?2, ?3, ?4 and ?5). DFT cal- culations indicate favorable energy barriers of hydrogen abstraction on terminal oxo species over vanadium oxide as compared to molybdenum oxide catalysts, which are 35.5 and 45.0 kcal/mol, respectively [21]. Since hydrogen abstraction is the rate-limiting step for most of the ODH reaction, the low energy barriers for vanadium oxides make them even more attractive candidates as ODH catalysts. We have been interested in the design, synthesis and properties of ODH catalysts derived from polyoxometalate based open-framework materials whose properties could possibly be rationalized in terms of their building blocks at the molecular level. During the on-going work, we recently reported a series of novel catalysts derived from vanadium oxide based nanostructured materials [M 3 V 18 O 42 (H 2 O) 12 (XO 4 )]Á24H 2 O (M = Fe, Co, Mn; X = V, S) for catalytic oxidative dehydrogenation of propane [22, 23]. Here we report a comparative study of the catalytic properties of a M. I. Khan (&) Á K. Aydemir Department of Biological, Chemical and Physical Sciences, Illinois Institute of Technology, 3101 S Dearborn Street Life Sciences Building Room 178, Chicago, IL 60616, USA e-mail: khan@iit.edu M. R. H. Siddiqui Á A. A. Alwarthan Chemistry Department, Science College, King Saud University, Riyadh 11451, Saudi Arabia C. L. Marshall Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, IL 60439, USA 123 Catal Lett (2011) 141:538–543 DOI 10.1007/s10562-011-0547-9