Catalytic performance of cobalt oxide-supported gold-palladium nanocatalysts for the removal of toluene and o-xylene

Abstract

Using the molten salt and polyvinyl alcohol-protected reduction method, we fabricated Co3O4 octahedron-supported Au-Pd (x(AuPdy)/Co3O4; x = (0.18, 0.47, and 0.96) wt%; y (Pd/Au molar ratio) = 1.85−1.97) nanocatalysts. The molten salt-derived Co3O4 sample possessed well-defined octahedral morphology, with an edge length of 300 nm. The Au-Pd nanoparticles, with sizes of 2.7−3.2 nm, were uniformly dispersed on the surface of Co3O4. The 0.96 (AuPd1.92)/Co3O4 sample showed the highest catalytic activity for toluene and o-xylene oxidation, and the temperature required for achieving 90% conversion of toluene and o-xylene was 180 and 187 °C, respectively, at a space velocity of 40000 mL/(g–h). The high catalytic performance of Co3O4 octahedron-supported Au-Pd nanocatalysts was associated with the interaction between Au-Pd nanoparticles and Co3O4 and high concentration of adsorbed oxygen species.