[Study on deactivation of Cu/Al-Ce-PILC in the selective catalytic reduction of NO by propylene].
New pillared clay catalysts were studied for NO removal by hydrocarbon in the presence of oxygen. The purpose of this work is to study the deactivation of Cu/Al-Ce-PILC in the SCR of NO. Montmorillonite was pillared by multi oligomeric hydroxyl cation to synthesize Al-Ce-PILC and treated by (NH4) 2SO4, then it was used as catalyst support. Cu/Al-Ce-PILC catalyst was prepared by impregnation and applied to the SCR of NO by C3 H6. The NO conversion to N2 reached its maximum of 56% at 350 degrees C and decreased to 22% at 700 degrees C. To study the deactivation of Cu/Al-Ce-PILC in the SCR of NO at high temperature, the fresh and post-reaction catalysts were characterized by XPS, TPR, TGA, Py-IR and DSC. The results showed that only Cu+ species existed on the fresh catalyst pretreated in hydrogen, while another species CuO was detected on the post-reaction catalyst. The loss of structural hydroxyl and SO4(2-) on Al-Ce-PILC weakened the surface acidity of the catalyst at high reaction temperature. Furthermore, the coke deposition on the catalyst covered part of the active sites and blocked the pores of the catalyst. The deactivation of Cu/Al-Ce-PILC may be due to the combined effects of CuO formation, the decrease on acidity and the coke deposition, which facilitated propylene combustion and inhibited NO reduction.
Lin
Qi-Chun
QC
Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084, China. linqichun@mail.tsinghua.org.cn
Hao
Ji-Ming
JM
Li
Jun-Hua
JH
Fu
Li-Xin
LX
Lin
Wei-Ming
WM
D000475:Alkenes / Q000737:chemistry*; D000537:Aluminum Oxide / Q000737:chemistry*; D000538:Aluminum Silicates / Q000737:chemistry; D002384:Catalysis; D002563:Cerium / Q000737:chemistry*; D000077215:Clay; D003300:Copper / Q000737:chemistry*; D009569:Nitric Oxide / Q000737:chemistry*; D010084:Oxidation-Reduction
D000475:Alkenes; D000538:Aluminum Silicates; D002563:Cerium; D009569:Nitric Oxide; C030583:ceric oxide; D003300:Copper; C013658:propylene; D000537:Aluminum Oxide; D000077215:Clay