کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
62683 | 47650 | 2009 | 9 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: The role of silver species on Ag/Al2O3 catalysts for the selective catalytic oxidation of ammonia to nitrogen The role of silver species on Ag/Al2O3 catalysts for the selective catalytic oxidation of ammonia to nitrogen](/preview/png/62683.png)
The role of Ag species on Ag/Al2O3 catalyst for the selective catalytic oxidation (SCO) of NH3 to N2 was studied using 10 wt% Ag/Al2O3 catalysts prepared with impregnation, incipient wetness impregnation and sol–gel methods. The catalyst characterization was preformed using N2 adsorption–desorption, UV/Vis, TEM and XRD. O2-chemisorption and H2–O2 titration were measured to confirm the metal dispersion on the catalyst. The Ag species state and Ag particle size have significant influence on the Ag/Al2O3 activity and N2 selectivity of the SCO of NH3 at low temperature. Ag0 is proposed to be an active species on the H2 pretreated catalyst at low temperature (<140 °C). It is evident that well-dispersed and small particle Ag0 enhances catalytic activity at low temperature, whereas large particle Ag0 is relate to a high N2 selectivity. In contrast, Ag+ could also be the active species at temperatures above 140 °C.
Various states of Ag species affected the low temperature activity of NH3 oxidation over the Ag/Al2O3 catalysts significantly.Figure optionsDownload high-quality image (75 K)Download as PowerPoint slide
Journal: Journal of Catalysis - Volume 261, Issue 1, 1 January 2009, Pages 101–109