Selective catalytic reduction of nitric oxide by ethylene in the presence of oxygen over Cu2+ ion-exchanged pillared clays

摘要: Abstract Cu 2+ ion-exchanged pillared clays are substantially more active than -ZSM-5 for selective catalytic reduction (SCR) of NO by hydrocarbons. More importantly, H 2 O (or SO ) has only mild effects on their activities. First results -exchanged TiO -pillared montmorillonite were reported this laboratory (Yang and Li, Ref. [1]), that showed overall activities two to four times higher -ZSM-5. A delaminated clay was subjected ion-exchange studied SCR C 4 in work. The Al 3 yielded rates both at temperatures above 400°C. peak conversion 90% 550°C a space velocity 15,000 h −1 (with = 2%). temperature decreased as the concentration increased. macroporosity partially responsible its (than laminated clays). At 1000 ppm each , peaked 2% all temperatures. caused deactivation, likely due competitive adsorption (of sites acid sites). high activity unique combination redox property strong Lewis acidity clay. suggested mechanism involved chemisorption (in presence 3+ -on pillars, activation form an oxygenated species.