You Mengyun, Wu Shufeng, Feng Xiaotong, Zhao Yong, Wang Yubin, Zhang Zhang
College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou Gansu, 730070, China.
Lanzhou Petrochemical Research Center, Petrochemical Research Institute, PetroChina, Lanzhou, 730060, China.
Environ Sci Pollut Res Int. 2025 Jan;32(2):936-948. doi: 10.1007/s11356-024-35751-z. Epub 2024 Dec 22.
The enhancement effect of Ce modification on VO-WO/TiO catalysts at low temperatures was investigated for the selective catalytic reduction (SCR) of NO with NH (NH-SCR). By adding 9% CeO to 0.5%VO-3%WO/TiO catalyst, the low-temperature denitrification performance of CeVWTi catalyst after Ce modification was significantly improved, achieving a NO conversion above 90% within a broad temperature range of 200-350℃, with catalytic activity comparable to that of 3% VO-3% WO/TiO. The catalysts were characterized by XPS, H-TPR, NH, and NO-TPD. The results indicated that the Ce additive could enhance the adsorption of NO on CeVWTi catalyst due to the synergetic interaction among the Ce and V, W species. The interaction between V and Ce also promoted the formation of V and Ce on the surface of the catalyst, which was conducive to enhancing the adsorption and oxidation capacity of the catalyst for NO. Additionally, the introduction of Ce led to a substantial deposition of nitrate species on the surface of the catalyst, especially the increase of nitrite species, which was beneficial to the NH-SCR reaction process, resulting in a significant enhancement of the catalyst's low-temperature catalytic activity.
研究了Ce改性对VO-WO/TiO催化剂在低温下以NH3选择性催化还原（SCR）NO（NH3-SCR）的增强作用。通过向0.5%VO-3%WO/TiO催化剂中添加9%CeO2，Ce改性后的CeVWTi催化剂低温脱硝性能显著提高，在200-350℃的宽温度范围内实现了90%以上的NO转化率，催化活性与3%VO-3%WO/TiO相当。采用XPS、H-TPR、NH3和NO-TPD对催化剂进行了表征。结果表明，由于Ce与V、W物种之间的协同作用，Ce添加剂可以增强CeVWTi催化剂对NO的吸附。V与Ce之间的相互作用还促进了催化剂表面V和Ce的形成，有利于提高催化剂对NO的吸附和氧化能力。此外，Ce的引入导致催化剂表面硝酸盐物种大量沉积，尤其是亚硝酸盐物种增加，这有利于NH3-SCR反应过程，从而显著提高了催化剂的低温催化活性。
