Formation of aluminum hydroxide by a hydrolytic reaction of nano aluminum powder synthesized by a pulsed wire evaporation (PWE) method has been studied. The type and morphology of the hydroxides were investigated with various initial pH and temperatures. The nano fibrous boehmite (AlOOH) was formed predominantly over 40 degrees C of the hydrolytic temperature, while the bayerite (Al(OH)(3)) was formed predominantly below 30 degrees C with a faceted crystalline structure. As a result, the boehmite showed a much larger specific surface area (SSA) than that of bayerite. The highest SSA of the boehmite was found about 409 m(2)/g. (c) 2006 Springer Science + Business Media, Inc.