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In Situ FT-IR Studies on the Mechanism of Selective Catalytic Reduction of NOx by Propene over SnO2/Al2O3 Catalyst

“…The loading of the Sn was fixed at 5% since the previous studies showed that the optimum Sn loading of 5% was most active for SnO 2 /Al 2 O 3 catalyst. 28 2.2. Catalytic Activity Evaluation.…”

Novel Sn–Ce/Al2O3 Catalyst for the Selective Catalytic Reduction of NOx Under Lean Conditions

“…It was found that the 5%Sn/Al 2 O 3 catalyst pre-treated in the reaction feed gas showed much higher activity than that without pre-treatment below 450°C. And above this temperature there is almost no deactivation after feed gas treatment [19]. For Sn/Al 2 O 3 catalyst, besides SnO 2 , Al 2 O 3 is an active site and contributes to the NO x reduction but could be prevented from doing so when its active centers are covered by dispersed SnO 2 [17].…”

“…The obtained gel was dried at 120°C for 24 h, followed by calcinations at 600°C for 4 h in air. The loading of Sn was fixed at 5% since previous research showed that the optimum Sn loading is 5% for Sn/Al 2 O 3 catalyst [19]. While that of Ce additive varies from 0.5 to 5%.…”

“…For Sn/Al 2 O 3 catalyst, besides SnO 2 , Al 2 O 3 is an active site and contributes to the NO x reduction but could be prevented from doing so when its active centers are covered by dispersed SnO 2 [17]. From the TEM photographs it can be seen that pre-treatment leads to the crystallization and growth of the SnO 2 species [19]. Due to the agglomeration, Al 2 O 3 surface sites previously covered by dispersed SnO 2 species are re-exposed.…”

“…Since SnO 2 was firstly reported to be an active catalyst for the NO x reduction by hydrocarbons in the presence of oxygen [14], some research was focused on Sn/Al 2 O 3 catalyst [15][16][17][18][19]. For Sn/Al 2 O 3 catalyst, the major disadvantage is that the NO x conversion is low at low-temperature region (250-400°C), However, there is little report about enhancing the low-temperature activity of Sn/Al 2 O 3 catalyst.…”