Synthesis of Reduced Graphene Oxide as a Support for Nano Copper and Palladium/Copper Catalysts for Selective NO Reduction by CO

Copper and palladium/copper nanoparticles supported on reduced graphene oxide catalysts were synthesized and evaluated for the selective NO reduction by CO. The catalysts were characterized by XRD, nitrogen adsorption-desorption, TGA, XPS, TPR, in situ XRD, STEM, and HRTEM. The STEM and HRTEM results showed high metal oxide dispersions on the rGO. XPS results showed the presence of Cu and Pd oxide species. The reduction of copper supported on the rGO occurred in two steps for CuOx/rGO(c), while that for CuOx-PdOy/rGO(c) occurred in one step for temperatures lower than 350 degrees C. Noteworthy is that the in situ XRD results showed that the rGO structure was not affected after reduction at 350 degrees C. The in situ XRD of reduction revealed the appearance of new phases for copper during the reduction. The catalysts were evaluated in NO reduction by CO. The tests showed that the reduced catalysts presented high performance with NO conversions and N-2 selectivity above 85% at 350 degrees C.