title: Economical way to synthesize SSZ-13 with abundant ion-exchanged Cu+ for an extraordinary performance in selective catalytic reduction (SCR) of NOx by ammonia.
abstract: In this study, an economical way for SSZ-13 preparation with the essentially cheap choline chloride as template has been attempted. The as-synthesized SSZ-13 zeolite after ion exchange by copper nitrate solution exhibited a superior SCR performance (over 95% NOx conversion across a broad range from 150 to 400 °C) to the traditional zeolite-based catalysts of Cu-Beta and Cu-ZSM-5. Furthermore, the opportune size of pore opening (∼3.8 Å) made Cu-SSZ-13 exhibiting the best selectivity to N2 as well as satisfactory tolerance toward SO2 and C3H6 poisonings. The characterization (XRD, XPS, XRF, and H2-TPR) of samples confirmed that Cu-SSZ-13 possessed the most abundant Cu cations among three investigated Cu-zeolites; furthermore, either on the surface or in the bulk the ratio of Cu(+)/Cu(2+) ions for Cu-SSZ-13 is also the highest. New finding was announced that CHA-type topology is in favor of the formation of copper cations, especially generating much more Cu(+) ions than the others, rather than CuO. The activity test of Cu(CuCl)-ZSM-5 (prepared by a solid-state ion-exchange method) clearly indicated that Cu(+) ions could make a major contribution to the low-temperature deNOx activity. The activity of protonic zeolites (H-SSZ-13, H-Beta, H-ZSM-5) revealed the topology effect on SCR performances.
authors.affiliation: State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology , Beijing 100029, China.
authors.forename: Biaohua
authors.initials: B
authors.lastname: Chen
authors.forename: Ruinian
authors.initials: R
authors.lastname: Xu
authors.forename: Runduo
authors.initials: R
authors.lastname: Zhang
authors.forename: Ning
authors.initials: N
authors.lastname: Liu
mesh_terms: D000393:Air Pollutants / Q000737:chemistry; D000397:Air Pollution / Q000032:analysis; D000641:Ammonia / Q000737:chemistry*; D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D007474:Ion Exchange; D015394:Molecular Structure; D009589:Nitrogen Oxides / Q000737:chemistry*; D017641:Zeolites
chemical_list: D000393:Air Pollutants; D009589:Nitrogen Oxides; D017641:Zeolites; D000641:Ammonia; D003300:Copper