Selective catalytic reduction of nitrogen oxides over a modified silicoaluminophosphate commercial zeolite  

作　　者：Carolina Petitto Gérard Delahay 

机构地区：[1]Institut Charles Gerhardt Montpellier,UMR 5253 CNRS/UM/ENSCM, Matériaux Avancés pour la Catalyse et la Santé, 8 rue de l'Ecole Normale

出　　处：《Journal of Environmental Sciences》2018年第3期246-252,共7页环境科学学报（英文版）

基　　金：the UREENOX project (ANR-11-VPTT-002) funded by the French ANR (L'Agence National de la Recherche);the French ANR for financial support;The Institute of Chemistry of Poitiers (IC2MP) for the management of the UREENOX project

摘　　要：Nitrogen oxides（NOx：NO,NO2）are a concern due to their adverse health effects.Diesel engine transport sector is the major emitter of NOx.The regulations have been strengthened and to comply with them,one of the two methods commonly used is the selective catalytic reduction of NOxby NH3（NH3-SCR）,NH3being supplied by the in-situ hydrolysis of urea.Efficiency and durability of the catalyst for this process are highly required.Durability is evaluated by hydrothermal treatment of the catalysts at temperature above 800℃.In this study,very active catalysts for the NH3-SCR of NOxwere prepared by using a silicoaluminophosphate commercial zeolite as copper host structure.Characterizations by X-ray diffraction（XRD）,scanning electron microscopy（SEM）and temperature programmed desorption of ammonia（NH3-TPD）showed that this commercial zeolite was hydrothermally stable up to 850℃ and,was able to retain some structural properties up to950℃.After hydrothermal treatment at 850℃,the NOxreduction efficiency into NH3-SCR depends on the copper content.The catalyst with a copper content of 1.25 wt.%was the most active.The difference in activity was much more important when using NO than the fast NO/NO2reaction mixture.Nitrogen oxides（NOx：NO,NO2）are a concern due to their adverse health effects.Diesel engine transport sector is the major emitter of NOx.The regulations have been strengthened and to comply with them,one of the two methods commonly used is the selective catalytic reduction of NOxby NH3（NH3-SCR）,NH3being supplied by the in-situ hydrolysis of urea.Efficiency and durability of the catalyst for this process are highly required.Durability is evaluated by hydrothermal treatment of the catalysts at temperature above 800℃.In this study,very active catalysts for the NH3-SCR of NOxwere prepared by using a silicoaluminophosphate commercial zeolite as copper host structure.Characterizations by X-ray diffraction（XRD）,scanning electron microscopy（SEM）and temperature programmed desorption of ammonia（NH3-TPD）showed that this commercial zeolite was hydrothermally stable up to 850℃ and,was able to retain some structural properties up to950℃.After hydrothermal treatment at 850℃,the NOxreduction efficiency into NH3-SCR depends on the copper content.The catalyst with a copper content of 1.25 wt.%was the most active.The difference in activity was much more important when using NO than the fast NO/NO2reaction mixture.

关 键 词：DIESEL Nitrogen oxides SCR process Copper ZEOLITE SILICOALUMINOPHOSPHATE 

分 类 号：O643.32[理学—物理化学]