Investigation of the Effect of Alumina Phase on Adsorptionand Distribution of Nano Pd Catalyst in Combustible GasDetection

Alumina is the most widely used as a remarkable choice for noble metal catalyst supportapplications in combustion of hydrocarbon gases due to its high thermal stability and Lewis acidsites on its surface. Variable features of ceramic support influence on adsorption, distribution andalso formation of appropriate phase of catalyst which result in sufficient gas detection. To preparePd/Al۲O۳, acidic solution includes ۵% mole Pd was impregnated in aqueous suspension ofalumina powder. This composition was calcined in air in ۵۰۰ . The as-prepared materials wascharacterized by scanning electron microscopy (SEM), nitrogen adsorption (BET) and X-raydiffraction (XRD). Dynamic gas test also was done to observe the catalyst performance followedby noble metal components reduction. According to the gas test results, catalytic characteristicsof metal components promoted as alumina surface area increased. Alumina particle size under ۵۰nm was found to be efficient in order to ensure suitable sensitivity of catalyst to oxidizecombustible gases.