Efficiency of Pd impregnated sol-gel derived γ-alumina porous spheres as catalyst

Abstract:

Porous γ-alumina spheres having surface area as large as 300 m²/gm are obtained by using sol-gel process. γ-alumina supported Pd catalyst is synthesized by soaking it in PdCl ₂ solution followed by drying and heating at 300 ^°C/1 hr in hydrogen atmosphere. Specific Surface Area of Pd coated alumina remained unaltered. The scanning electron microscopy revealed uniform coating of Pd metal on the surface. The equivalent spherical diameter (ESD) of the coated Pd metal particles is estimated to be 50. The catalytic efficiency is evaluated by H ₂ -O ₂ combination reaction. The performance of this supported catalyst is found to be much superior in comparison with Pd catalyst realized on commercially available alumina having surface area of 80 m²/gm. The improved efficiency of the catalyst could be co-related to enhanced surface of nano-structured Pd available for catalytic action. The added advantage of spherical shape of the support material appeared in uniform and homogeneous loading of the catalyst bed. The results highlight the important role played by support material in these type of catalysts.