With the rapid development of industrialization, the emission of nitrogen oxides (NO
x) has become a global environmental issue. Uranium is the primary fuel used in nuclear power generation. However, the production of uranium, typically based on the uranyl nitrate method, usually generates large amounts of nitrogen oxides, particularly NO
2, with concentrations in the exhaust gas exceeding 10,000 ppm. High concentrations of nitrogen dioxide are also produced during silver electrolysis processing and the treatment of waste electrolyte solutions. Traditional V-W/TiO
2 NH
3-SCR catalysts typically exhibit high catalytic activity at temperatures ranging from 300 to 400 °C, under conditions of low NO
x concentrations and high gas hourly space velocity. However, their performance is not satisfying when reducing high concentrations of NO
2. This study aims to optimize the traditional V-W/TiO
2 catalysts to enhance their catalytic activity under conditions of high NO
2 concentrations (10,000 ppm) and a wide temperature range (200–400 °C). On the basis of 3 wt% Mo/TiO
2, various loadings of V
2O
5 were selected, and their catalytic activities were tested. Subsequently, the optimal ratios of active component vanadium and additive molybdenum were explored. Simultaneously, doping with WO
3 for modification was selected in the V-Mo/TiO
2 catalyst, followed by activity testing under the same conditions. The results show that: the NO
x conversion rates of all five catalysts increase with temperature at range of 200–400 °C. Excessive loading of MoO
3 decreased the catalytic performance, with 5 wt% being the optimal loading. The addition of WO
3 significantly enhanced the low-temperature activity of the catalysts. When the loadings of WO
3 and MoO
3 were both 3 wt%, the catalyst exhibited the best denitrification performance, achieving a NO
x conversion rate of 98.8% at 250 °C. This catalyst demonstrates excellent catalytic activity in reducing very high concentration (10,000 ppm) NO
2, at a wider temperature range, expanding the temperature range by 50% compared to conventional SCR catalysts. Characterization techniques including BET, XRD, XPS, H
2-TPR, and NH
3-TPD were employed to further study the evolution of the catalyst, and the promotional mechanisms are explored. The results revealed that the proportion of chemisorbed oxygen (O
α) increased in the WO
3-modified catalyst, exhibiting lower V reduction temperatures, which are favorable for low-temperature denitrification activity. NH
3-TPD experiments showed that compared to MoO
x species, surface WO
x species could provide more acidic sites, resulting in stronger surface acidity of the catalyst.
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