Green Method of Preparing High Surface Area Boehmite

High surface area boehmiteAlO(OH) are widely used in the industry of adsorbents, catalysts and catalyst carriers [1]. Various synthesis methods are possible for boehmite. It can be prepared by the sol-gel process using aluminum alkoxides [2]. However, the synthetic route used industrially involves the precipitation of aluminum salts, which may be followed by a period of ripening in hydrothermal conditions [3]. At the present investigation, a green, inexpensive and straightforward method for the synthesis of high surface area boehmite has been described. Our studies showed that walnut shell powder as an agricultural wastecan be used as the hard template and aluminium nitrate as source of alumina in aqueous media to synthesis boehmite and characterized using powder X-ray diffraction, thermal analysis and N2 adsorption/desorption. Synthesized mesoporousboehmite has high specific surface area (304 m2/g), narrow pore size diameter (3.32 nm) and high pore volume (70 cm3/g). The presence of walnut shell in the precursors of boehmite is critical for the formation of high surface area mesoporous structure. Furthermore, γ-alumina supported vanadium, molybdenum and tungsten catalyst obtained from calcination of hard-templatedboehmite was prepared by impregnation method, and its catalytic performance in the oxidation of alcohols was also investigated.