The Open Catalysis Journal, 2011, 4, 9-17 9 1876-214X/11 2011 Bentham Open Open Access Catalytic Conversion of Isopropanol and CO Oxidation in Presence of NiO Supported on Modified Cordierite S.A. El-Molla *,1 , G.A. El-Shobaky 2 , Y.M. Fahmy 2 and H.G. El-Shobaky 3 1 Chemistry Department, Faculty of Education, Ain Shams University, Roxy, Heliopolis, Cairo 11757, Egypt 2 National Research Center, Dokki, Cairo, Egypt 3 Chemistry Department, Faculty of Science, Cairo University, Cairo, Egypt Abstract: A commercial cordierite sample showed a small catalytic activity in isopropanol conversion carried out at 150- 350 ºC and no measurable activity in CO oxidation by O 2 . On the other hand, supporting NiO on Al 2 O 3 –modified cordierite resulted in the formation of an active solid that having good catalytic activity in isopropanol conversion and CO oxidation by O 2 . These two reactions were carried out at 150-350 and 200 ºC, respectively. The results revealed that the catalyst containing 5% (w/w) NiO showed the highest activity in the alcohol conversion and acted as selective dehydration catalyst. The catalyst sample containing 20% NiO (w/w) exhibited a good activity in CO oxidation by O 2 which decreased progressively by increasing its calcination temperature within 350-600 ºC. Al 2 O 3 –treated cordierite dissolved a portion of NiO in its lattice, increasing the calcination temperature within 350-600 ºC increases the dissolution of NiO in the matrix of Al 2 O 3 –modified cordierite system. Keywords: EDX, Catalytic activity, NiO/Cordierite, Al 2 O 3 -treatment. INTRODUCTION Supported transition metal oxides constitute an interesting class of catalytic materials. These materials are used in many important industrial and environmental applications such as CO oxidation [1], N 2 O decomposition [2], methane steam reforming [3], dehydration and dehydrogenation of alcohols [4]. The catalytic activity and selectivity of the oxide catalyst can be modified by loading on different support materials [5, 6]. The interaction between the support and transition metal oxide can take place via of formation metal aluminate in case of alumina- support, or solid solution in case of MgO support [7,8] having small catalytic activity if compared to metal oxide-supported solid. For this reason it is important to study the possibility of obtaining membranes which can not react with the catalytically active phase (transition metal oxide) and with low cost to be economic. Cordierite (Mg 2 Al 4 Si 5 O 18 ) is a crystalline magnesium aluminosilicate and is one of the phases of MgO-SiO 2 -Al 2 O 3 [9]. This material has low cost, low pressure drop in the exhaust system, good thermal resistance and low expansion coefficient [10]. These properties characterize cordierite as a potentially available material employed in electronic industry [10]. Also, cordierite is commercial material for high temperature catalyst applications, specially for automotive catalysts due its high mechanical stability and low thermal expansion coefficient [11]. As a rule cordierite has a low specific surface area that could be increased by treatment with *Address correspondence to this author at the Chemistry Department, Faculty of Education, Ain Shams University, Roxy, Heliopolis, Cairo 11757, Egypt; Tel: +202 24558087; Fax: +202 22581243; E-mail: saharelmolla@yahoo.com alumina [12]. The big surface area is very desirable. It has been shown that the increase of the total surface area of the monolith is the most effective way to increase the conversion of automotive pollutants for a given loading of precious metals [13]. Cordierite has been successfully used as a catalyst support for Co 3 O 4 , Mn 2 O 3 , CuO, Fe 2 O 3 and NiO [1, 14, 15]. This work aims at studying the physicochemical surface and catalytic properties of NiO supported on cordierite support material. The effects of extent of NiO-loading, calcination temperature and treating cordierite with Al 2 O 3 using a washcoating technique on its physicochemical surface and catalytic properties have been investigated [16]. Different physicochemical surface and catalytic properties of NiO supported on Al 2 O 3 –modified cordierite support material were investigated using XRD, EDX, nitrogen adsorption at -196 o C and catalytic conversion of isopropanol at 150- 350 o C using the flow method and CO oxidation by O 2 at 200 o C. EXPERIMENTAL Sample Preparation A commercial cordierite (Mg 2 Al 4 Si 5 O 18 ) supplied by Baikowski Inc. company was treated with 25% Al 2 O 3 (w/w) using a washcoating technique. A given mass of aluminum ethoxide was dissolved in a convenient volume of ethanol and few drops of HCl (28%) and subjected to stirring for 60 min. A calculated amount of cordierite was then impregnated with alcoholic solution of aluminum ethoxide and stirred for 30 min. at 60 o C. The obtained solid was dried at 110 o C till constant weight. The dried solid was used as a catalyst support for NiO. The Al 2 O 3 -treated cordierite sample was then impregnated with calculated amounts of nickel nitrate