view:30255 Last Update: 2018-2-14
Parvaneh Nakhostin Panahi, Ali Niaei, Hui-Hsin Tseng, Darush Salari, Seyed Mahdi Mousavi, Gérard Delahay
Ultrasound-assistant preparation Cu-SAPO-34 nanocatalyst for selective catalytic reduction of NO by NH3 |
The influence of the various preparation methods of Cu-SAPO-34 nanocatalysts on the selective catalytic reduction of NO with NH3 under excess oxygen has been studied. Cu-SAPO-34 nanocatalysts were prepared by using four techniques: conventional impregnation (IM), ultrasound-enhanced impregnation (UIM), conventional deposition precipitation (DP) using NaOH and homogeneous deposition precipitation (HDP) using urea. These catalysts were characterized in detail by various techniques such as N2-sorption, XRD, TEM, H2-TPR, NH3-TPD and XPS to understand the catalysts structure, nature and the dispersed state of copper species, and NH3 adsorption acid sites. All of the nanocatalysts showed high activities for NO removal. However, the activities were different and follow the sequence of Cu-SAPO-34 (UIM) > Cu-SAPO-34 (HDP) > Cu-SAPO-34 (IM) > Cu-SAPO-34 (DP). Based on the obtained results, it was concluded that the NO conversion on Cu-SAPO-34 nanocatalysts are mainly related with the easily reducibility of the isolated Cu2+ ions and CuO species, acid sites number of the catalysts and dispersion of CuO species on SAPO-34. |