Improvement on the for the poisoning resistance of commercial de-NO_xSCR catalyst

To improve the resistance towards alkali metal poisoning,Ni or Zr with different concentrations was introduced to commercial SCR catalysts by a wet impregnation. The catalysts before and after modifications were characterized by energy dispersive spectrometry( EDS),N2adsorption-desorption,X-ray powder diffraction( XRD),Fourier-transform infrared spectroscopy( FTIR),temperature-programmed reduction( TPR) and X-ray photoelectron spectroscopy( XPS).Results show that the modifications of the catalysts significantly improved their resistance towards K poisoning. Ni and Zr were doped sucessfully into the commercial catalysts,and the crystalline structure of the catalysts was maintained. FTIR results showed that the catalysts doped with Ni formed new Lewis acid sites. Brnsted acid sites were strengthened by loading Zr.The increased acid sites might be the reason why the catalysts after modification showed higher resistance to K poisoning.H2-TPR and XPS results showed enhanced Redox properties of the catalysts after doping which balanced the negative effect of the reduced specific surface area.