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The modification of Ag/Al 2 O 3 catalyst and application of combined catalysts in methanol‐SCR of NO
Author(s) -
Zou Sha,
Cao Yi,
Lan Li,
Sun Mengmeng,
Chen Sijie,
Yang Zhengzheng,
Xu Baoqiang,
Chen Yaoqiang
Publication year - 2015
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.22328
Subject(s) - catalysis , methanol , tungsten , space velocity , materials science , selective catalytic reduction , inorganic chemistry , nuclear chemistry , chemistry , metallurgy , selectivity , organic chemistry
In this paper, a series of W x /Ag/Al 2 O 3 catalysts with different tungsten contents (0, 0.04, 0.06, 0.08, and 0.10 g/g) and 0.03 g/g silver for selective catalytic reduction of NO with methanol under excess oxygen (methanol‐SCR), were prepared with a traditional impregnation method. At a gas hourly space velocity (GHSV) of 30 000 h −1 , the operating window of NO conversion (NO conversion above 50 %) shifted to a higher temperature region as the tungsten content increased. Importantly, the operating window of NO conversion over combined catalysts containing W 8 /Ag/Al 2 O 3 in the front and Ag/Al 2 O 3 in the rear (W 8 /Ag/Al 2 O 3 + Ag/Al 2 O 3 ), was wider (65 °C) than that of the single W 8 /Ag/Al 2 O 3 catalyst (50 °C) or Ag/Al 2 O 3 catalyst (41 °C). Further, the CO concentration over the combined catalyst was lower than the single W 8 /Ag/Al 2 O 3 catalyst. The characterization results demonstrated that there are strong interactions between tungsten and silver which contribute to the formation and stabilization of oxidized silver species.