| With the development of modern society, many proceses, such as steel making, electric power generation, the operation of car engines and incineration of municipal refuse are emitting more and more gases, The removal of nitrogen oxides (NOx) is one of the hot points in the area of enrionmental pollution treatment because NOx are very harmful and hard to be removed. Among various denitrification methods, catalytic decomposition and selective catalytic reduction (SCR) were adopted widely. SCR technology with ammonia as reducing agent has being widely used commercially for denitrification of flue gas.At present, Relatively mature NH3-SCR catalyst is vanadium-based catalysts, which has higher catalytic activity , sulfur tolerance and the operating temperature for 300-400℃. The device of denitration is located before the dust removal and desulfurization, The concentration of soot and SO2 is high in flue gas and is easy to poison the catalyst, resulting in the higher operating costs. In recent years, there is an interest in developing a potential low-temperature (lower than 250℃) SCR catalyst, and then the catalyst bed can be moved downstream of the desulfurization scrubber and particulate control device, where most of sulfur dioxide and dust is removed and the deactivation is weakened.Two catalysts system, ten kinds of catalysts were prepared and evaluated in this study. All the catalyst systems were evaluated using a fixed-bed catalytic reactor. Each system of the catalysis systems are characterized by XRD. GC is used to detect the selectivity of N2. The study found that these two catalysts systems have firely good low-temperature selective catalytic reduction performance, at 80℃, NO conversion and selectivity of N2 is up to 90% and 60%. at 120℃, NO conversion rate is up to 100 percent. The two kinds of composite metal oxide catalysts are excellent NH3-SCR catalyst.
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