• Journal of the Korean Applied Science and Technology
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• v.31 no.2
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• pp.313-319
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• 2014

This study was performed to obtain high conversion efficiency of $NH_3$ and minimize generation of nitrogen oxides using metal-supported catalyst with Ag : Cu ratio. Through structural analysis of the prepared catalyst with Ag : Cu ratio ((10-x)Ag-xCu ($0{\leq}x{\leq}6$)), it was confirmed that the specific surface area was decrease with increasing metal content. A prepared catalysts showed Type II adsorption isotherms regardless of the ratio Ag : Cu of metal content, and crystalline phase of $Ag_2O$, CuO and $CuAl_2O$ was observed by XRD analysis. In the low temperature($150{\sim}200^{\circ}C$), a conversion efficiency of AC_10 recorded the highest(98%), whereas AC_5 (Ag : Cu = 5 : 5) also showed good conversion efficiency(93.8%). However, in the high temperature range, the amounts of by-products(NO, $NO_2$) formed with AC_5 was lower than that of AC_10. From these results, It is concluded that AC_5 is more environmentally and economically suitable.

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.4
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• pp.379-386
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• 2011

Catalyst-assisted plasma system with a DBD (Dielectric Barrier Discharge) reactor was used to remove hydrogen sulfide, which is one of the odorous species in this study. The ${\gamma}-Al_2O_3$ and ${\beta}$-Zeolite catalysts impregnated by Ag, Cu and Mn species were employed as catalysts and their $H_2S$ removal characteristics under plasma irradiation were investigated. From the experimental study, we found that the $H_2S$ removal efficiency increases with decreasing space velocity in the system and increasing specific input energy. Furthermore, ${\beta}$-Zeolite catalysts are efficient to remove $H_2S$ than ${\gamma}-Al_2O_3$ catalysts. Especially, the catalysts impregnated by Ag have higher removal efficiency than other catalysts (Cu, Mn).

• Journal of the Korean Institute of Gas
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• v.19 no.5
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• pp.20-28
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• 2015

This work investigated the size and shape effect of ${\gamma}$-alumina-supported metal oxides on the hydrocarbon selective catalytic reduction of nitrogen oxides. Several metal oxides including Ag, Cu and Ru were used as the catalysts, and n-heptane as the reducing agent. For the Ag/${\gamma}$-alumina catalyst, the $NO_x$ reduction efficiency in the range of $250{\sim}400^{\circ}C$ increased as the size of Ag decreased (20 nm>50 nm>80 nm). The shape effect of metal oxides on the $NO_x$ reduction was examined with spherical- and wire-shape nanoparticles. Under identical condition, higher catalytic activity for $NO_x$ reduction was observed with Ag and Cu wires than with the spheres, while spherical- and wire-shape Ru exhibited similar $NO_x$ reduction efficiency to each other. Among the metal oxides examined, the best catalytic activity for $NO_x$ reduction was obtained with Ag wire, showing almost complete $NO_x$ removal at a temperature of $300^{\circ}C$. For Cu and Ru catalysts, considerable amount of NO was oxidized to $NO_2$, rather than reduced to $N_2$, leading to lower $NO_x$ reduction efficiency.