In this paper, the lower-temperature (200 °C) SCR performance of modulated 1%V₂O₅-5%WO₃/TiO₂ catalysts with different Cr₂O₃ amount was investigated. Results showed that addition of an appropriate amount of Cr₂O₃ component (< 5 wt%) can improve the NO reaction rate constant k of modulated VW/Cr/Ti catalysts with forming lower N₂O concentration. The interaction between VO_x or WO_x species and CrO_x species reduced the degree of polymerization of VO_x and WO_x species, thus promoting the formation of V–O-W bonds. The formation of V–O–Cr and V–O–W bonds increased the redox type of VO_x and the amount of B acid, so the doping of Cr₂O₃ (< 5 wt%) improved the catalytic performance of V₂O₅-WO₃/TiO₂ catalyst. After excessive Cr₂O₃ (> 5 wt%) was added, the crystal phase Cr₂O₃ was formed, which weakened the formation of V–O–W and V–O–Cr bonds, and promoted the oxidation of NH₃, thereby reducing the catalytic activity. In addition, Cr₂O₃ modified V₂O₅-WO₃/TiO₂ still had a high catalytic activity, high stability, and low N₂O generation under the reaction conditions of 10% H₂O and 100 ppm SO₂.

本文研究了不同Cr ₂ O ₃用量的调制1%V ₂ O ₅ -5%WO ₃ /TiO ₂催化剂的低温（200 ℃）SCR性能。结果表明，添加适量的Cr ₂ O ₃组分（< 5 wt%）可以提高调制VW/Cr/Ti催化剂的NO反应速率常数k，同时形成较低的N ₂ O浓度。_{VO x}或WO _x物种与CrO _x物种之间的相互作用降低了VO _x和WO _x的聚合度种，从而促进V-OW键的形成。V-O-Cr和V-O-W键的形成增加了VO _x的氧化还原类型和B酸的量，因此Cr ₂ O _{3 (< 5 wt%)的掺杂提高了V 2}的催化性能O ₅ -WO ₃ /TiO ₂催化剂。添加过量的Cr ₂ O _{3 (> 5 wt%)后，形成Cr 2} O ₃晶相，削弱了V-O-W和V-O-Cr键的形成，促进了NH ₃的氧化，从而降低催化活性。此外，Cr ₂ O ₃改性V ₂ O ₅ -WO ₃ /TiO _{2在10% H 2} O和100 ppm SO ₂的反应条件下仍具有高催化活性、高稳定性和低N ₂ O生成。