Regeneration of sulfur poisoning Cu-Ir/H-ZSM-5catalyst in catalytic reduction of NO_x with propane by H₂ reduction

Effect of regeneration parameters of H₂ reduction on sulfur poisoning Cu-Ir/H-ZSM-5catalyst for catalytic reduction of NO_x with propane (C₃H₈-SCR) was investigated. The regeneration behavior was carried out by N₂ adsorption, X-ray diffraction (XRD), X-ray photoelectron spectrometer (XPS) and hydrogen temperature-programmed reduction (H₂-TPR). Deactivation of Cu-Ir/H-ZSM-5was caused by the formation of CuSO₄, resulting in the loss of the active sites, decrease of the surface area, microspore area and pore volume of catalyst. The temperature of 500℃ and regeneration gas consumption of 42.8 L/gcatalyst were the best regeneration condition for H₂ reduction, because of the lowest content (0.4%) of CuSO₄ on Cu-Ir/H-ZSM-5catalyst. The activity of Cu-Ir/H-ZSM-5catalyst regenerated could be returned to 95% of the fresh catalyst. The increase of the surface area, microspore area, and pore volume of catalyst was obtained by H₂ reduction.