The influence of precursors on Rh/SBA-15 catalysts for N2O decomposition

Series of Rh/SBA-15 catalysts were prepared by impregnation and grafting method applying different Rh precursors. The catalytic behaviors of N2O decomposition over these catalysts were tested in an automated eight flow reactor system. The catalysts were characterized by X-ray fluorescence spectroscopy (XRF), X-ray diffraction (XRD), N2 adsorption/desorption, transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) techniques. The results showed that the dispersion of Rh species on the catalysts is closely related to the molecular size and the hydrophobic property of the precursors comparing to the hydrophilic support, better dispersion results were found in catalysts by impregnation of smaller precursors, while by grafting better dispersion resulted from big precursor. On the other hand, the activities of the catalysts match well with the Rh dispersion status. Rh/SBA-15-CDCR starting from [(CO)2RhCl]2 showed good dispersion and gave the best N2O decomposition activity.