Selective catalytic reduction of NOx by C2H5OH over Ag/Al2O3/cordierite: Effect of the surface concentration of silver

Role of active components of an Ag/Al2O3/cordierite catalyst in selective reduction of NO by ethanol

“…The temperature dependences of NO conversion for the studied Ag/Al 2 O 3 /cordierite catalysts are described by bell-shaped curves that are typical for an NO SCR process [5]. Table 1 shows the values of the maximum NO conversion and the temperature intervals in which maximum conversion is achieved.…”

“…with distilled water, the samples were dried at 110°C and calcined at 550°C for 3 h. Aluminum oxide was formed on the surface as a mixture of the h and g modifications of Al 2 O 3 [5]. Silver was deposited by the incipient wetness method for the Al 2 O 3 /cordierite samples obtained, using an aqueous solution of AgNO 3 , followed by drying and calcination at 730°C for 3 h. The prepared samples of Ag/Al 2 O 3 /cordierite contained from 0.1 to 2 wt.% Ag and from 18 to 54 wt.% Al 2 O 3 on the structured cordierite support.…”

Selective Reduction of No By C3 and C8 Alkanes Over Silver Catalysts on Structured Al2O3/Cordierite Supports

“…Samples of silver-alumina catalysts deposited on a structured support from cordierite were prepared by the previously developed method [7,8], in which the optimum concentration of Al 2 O 3 amounts to 45-50 wt.%. The prepared Ag/Al 2 O 3 /cordierite catalysts contained 0.1, 0.3, 0.5, and 1.0 wt.% of silver and 46 wt.% of alumina.…”

“…The investigations were carried out with a gas mixture with the composition (vol.%) 0.05NO + 0.2HC 1 (C 3 H 8 or C 8 H 18 ) + 10.0O 2 + He with a volume flow rate of 48000 h -1 in the presence of water vapor (2.0 vol.%). The NO was analyzed by means of a gas analyzer with a chemiluminescence detector, and the other reactants were analyzed by chromatography (thermal conductivity detector).In order to study the acidic characteristics of the active phase of the catalysts by IR spectroscopy Ag/Al 2 O 3 samples were prepared by analogy with the method in [7,8]; they contained 0.2, 0.6, and 1.2 wt.% of Ag, which is close in the ratio of the components to the active phase of the investigated structured catalysts. The samples in the form of tablets were submitted to preliminary heat treatment under vacuum at 400°C for 1 h, after which the background IR spectrum at room temperature was 122 0040-5760/15/5102-0122…”

“…Silver-alumina catalysts have been widely investigated for the selective catalytic reduction (SCR) of nitrogen oxides by the C 3 -C 10 hydrocarbons that are products from incomplete combustion of the fuel [3-6]. The effectiveness of block catalysts with honeycomb structure Ag/Al 2 O 3 /cordierite in the SCR of NO by ethanol and butanol, which can be components of motor fuel, was demonstrated in [7-9]; the effect of the composition of the catalysts on their activity was determined.In the present work the role of the silver in structured Ag/Al 2 O 3 /cordierite catalysts in SCR of NO by propane and octane, i.e., in reaction mixtures close in composition to exhaust gases, was investigated.Samples of silver-alumina catalysts deposited on a structured support from cordierite were prepared by the previously developed method [7,8], in which the optimum concentration of Al 2 O 3 amounts to 45-50 wt.%. The prepared Ag/Al 2 O 3 /cordierite catalysts contained 0.1, 0.3, 0.5, and 1.0 wt.% of silver and 46 wt.% of alumina.…”