A systematic and effective method for the regeneration of thermally deactivated commercial monolith SCR catalyst was investigated. Herein, two types of regenerated solutions, namely NH4Cl (1 mol/L) and dilute H2SO4 (0.5 mol/L), were employed to treat the used catalyst. The influences of temperature and regeneration process on the structural and textural properties of the target catalyst were determined by X-ray diffraction, scanning electron microscope, N2 adsorption/desorption, elements analysis and fourier transform infrared spectroscopy techniques. The results suggest that the anatase phase of the used catalyst is still maintained after heat treatment. The catalytic activity increases to some extent after regeneration. And the catalyst regenerated by NH4Cl aqueous solution presents a higher activity than that of by dilute H2SO4 solution. The main reason is that the NH3 derived from the NH4Cl decomposition at high temperature can be adsorbed on the catalyst, and hence promote reaction process. The aggregated V2O5 is able to partly re-disperse through the regeneration process, and the ammonia intrinsic oxidation under high concentration of O2 is a potential factor that suppresses the catalytic activity.
