Catalytic inorganic membrane preparation and the catalytic oxidation of o-xylene contained in air streams on catalytic membrane tubes are presented in this study. Boehmite prepared sols were deposited onto porous alumina tubes from the outside using a filtration coating technique. The coatings were characterized by nitrogen gas permeations at the same temperatures used for the o-xylene experiments. Single gas permeabilities indicated a best separation factor for the modified membrane for H-2/N-2 of 3.6, which is very close to the Knudsen value. Pt loading was estimated as 1.6%w/w based on membrane material weight by using both weighing and atomic absorption spectrophotometry (AAS) methods. O-ylene catalytic oxidation of o-xylene contained in air streams with concentrations between 0.146-0.220% (v/v) was carried out in a catalytic membrane reactor at temperatures between 150-290degreesC and 97% conversion was achieved for 0.146% o-xylene in air at a temperature of 285degreesC.