Effect of Nano-support and Type of Active Metal on Reforming of CH 4 with CO 2 Ahmed Sadeq Al-Fatesh,* Muhammad Awais Naeem, Wasim Ullah Khan, Ahmed Elhag Abasaeed and Anis Hamza Fakeeha Chemical Engineering Department, College of Engineering, King Saud University, P.O. Box 800, Riyadh 11421, Kingdom of Saudi Arabia (Received: Aug. 20, 2013; Accepted: Nov. 19, 2013; Published Online: Jan. 20, 2014; DOI: 10.1002/jccs.201300431) Two series of Co and Ni based catalysts supported over commercial (ZrO 2 , CeO 2 , and Al 2 O 3 ) nano sup- ports were investigated for dry reforming of methane. The catalytic activity of both Co and Ni based cata- lysts were assessed at different reaction temperatures ranging from 500–800 °C; however, for stability the time on stream experiments were conducted at 700 °C for 6 h. Various techniques such as N 2 adsorption- desorption isotherm, temperature-programmed reduction (H 2 -TPR), temperature-programmed desorption (CO 2 -TPD), temperature-programmed oxidation (TPO), X-ray diffraction (XRD), thermogravimetric analysis (TGA) were applied for characterization of fresh and spent catalysts. The catalytic activity and stability tests clearly showed that the performance of catalyst is strongly dependent on type of active metal and support. Furthermore, active metal particle size and Lewis basicity are key factors which have signifi- cant influence on catalytic performance. The results indicated that Ni supported over nano ZrO 2 exhibited highest activity among all tested catalysts due to its unique properties including thermal stability and re- ducibility. The minimum carbon deposition and thus relatively stable performance was observed in case of Co-Al catalyst, since this catalyst has shown highest Lewis basicity. Keywords: CO 2 /CH 4 Reforming; Nano-supports; Activity; Stability; Coke; Ni; Co. INTRODUCTION High chemical stability and huge transportation cost of methane, major component of natural gas, from remote regions to industrial complexes have restricted its wider in- dustrial applications. To overcome these difficulties, nu- merous research activities and technologies are in progress to transform methane into various valuable commercial products via direct and/or indirect methane chemical con- version routes. 1,2 The indirect transformation of methane, via synthesis gas (mixture of H 2 and CO) route, to other liq- uid hydrocarbons has gained world-wide attention from the last decade. 3,4 There are several methods for the conversion of methane into syngas for example partial oxidation using oxygen, carbon dioxide reforming (also named dry meth- ane reforming) and steam reforming. 3,5 However as com- pared to other syngas production processes, dry methane reforming (DMR) reaction is industrially advantageous since it yields syngas with H 2 /CO product ratio close to unity which is more suitable for liquid hydrocarbon pro- duction via Fischer–Tropsch synthesis and in the produc- tion of oxygenated compounds. 6,7 The main drawback of DMR is its endothermic nature which requires fairly high temperatures to achieve high conversion values. These se- vere operating conditions cause catalyst deactivation which results due to accumulation of coke over catalyst surface and/or sintering of the active metal particles. 8,9 Many re- search efforts have been focused on developing metal sup- ported catalysts with high catalytic performances towards syngas production and high resistance to carbon deposi- tion. Noble metal based catalysts have high catalytic per- formance in terms of methane conversion and selectivity to syngas, and are less sensitive to carbon formation. 10 How- ever, non-noble transition metals, such as Ni and Co, are often preferred due to their low cost and more availability compared to noble metals. 8,11 DMR reaction has employed various oxides as carriers such as SiO 2 , Al 2 O 3 , TiO 2 , CeO 2 , ZrO 2 , MgO etc. and binary or ternary oxides. 12-15 Generally the oxides with more basic sites exhibit better catalytic per- formance in terms of coke suppression. 14 Catalyst perfor- mance in terms of activity and stability is significantly af- fected by the support material in DMR process. 16 The spe- cific role of catalyst support is to provide a large surface area, high thermal stability, maintain high dispersion of the active metal particles and promote stability against sintering and carbon deposition. 17 It is a well-known fact that during DMR reaction the oxygen supply to active metal results in J. Chin. Chem. Soc. 2014, 61, 461-470 © 2014 The Chemical Society Located in Taipei & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim 461 JOURNAL OF THE CHINESE CHEMICAL SOCIETY Article * Corresponding author. Tel: 009661-4676859; Fax: 009661-4678770; Email: aalfatesh@ksu.edu.sa