Promotion of Ag/H-BEA by Mn for lean NO reduction with propane at low temperature.
Effects of adding manganese to Ag/H-BEA for selective catalytic reduction of NO(x) with propane (C(3)H(8)-SCR) were investigated under a lean-burn condition. Mn addition significantly promotes the catalytic performance of Ag/H-BEA below 673 K. A Ag-Mn/H-BEA catalyst with equal metal weight of 3 wt % has the highest activity for C(3)H(8)-SCR among samples with a different bimetal loading. Manganese is mainly present in the 3+ and 4+ oxidation states in Ag-Mn/H-BEA catalysts. The major contributions of manganese suggested by the data presented in this paper are to catalyze the NO oxidation and stabilize silver in a dispersed Ag(+) state. The presence of silver enforces the transformation of a certain amount of Mn(3+) ions to Mn(4+) ions. The activity of Ag-Mn/H-BEA decreases slightly at low SO(2) concentrations (0-200 ppm) but decreases significantly at high SO(2) concentrations (400-800 ppm). In the presence of 10% H(2)O and 200 ppm SO(2), the inhibition of C(3)H(8)-SCR below 673 K is more significant than that at high temperature above 673 K. Ag-Mn/H-BEA is a promising catalyst for the removal of NO(x) from diesel engine exhaust.
Pan
Hua
H
Department of Chemical and Biochemical Engineering, Zhejiang University (Xixi Campus), Hangzhou 310028, P.R. China.
Su
Qingfa
Q
Chen
Jie
J
Ye
Qing
Q
Liu
Yiting
Y
Shi
Yao
Y
D003080:Cold Temperature; D008345:Manganese / Q000737:chemistry*; D009569:Nitric Oxide / Q000737:chemistry*; D010084:Oxidation-Reduction; D011407:Propane / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D013431:Sulfates / Q000737:chemistry; D014867:Water / Q000737:chemistry; D017641:Zeolites / Q000737:chemistry
D013431:Sulfates; D014867:Water; D017641:Zeolites; D009569:Nitric Oxide; D012834:Silver; D008345:Manganese; D011407:Propane