A novel tungsten-doped magnetic iron oxide catalyst was fabricated for selective catalytic reduction of NO_x with NH₃ (NH₃-SCR), which was supported by carbon-included magnetic materials of Fe₂O₃–-H synthesized by the solution combustion followed by the oxidization of hydrogen peroxide. As a consequence, the thermal stability of γ-Fe₂O₃ crystallites located in the magnetic support is significantly enhanced. Meanwhile, the irreversible transformation of Fe₂O₃ crystallites from γ-phase to α-phase during the annealing process at high temperatures (i.e. 400 °C) is restrained to a large extent. In addition, the magnetic W/Fe₂O₃ catalyst presents a superb porous structure with higher BET surface area and pore volume due to the anti-sintering effect of tungsten doping on the magnetic Fe₂O₃. In this regard, the surface acidity as well as the molar ratio of the surface-adsorbed oxygen is substantially augmented, leading to a remarkable improvement of the redox ability of the active bulk species in the catalyst. It is worth mentioning that the promotions in thermal stability and redox ability is affected by the doping amount of tungsten in the catalyst, the molar ratio of glucose/urea/iron, and the ignition temperature for synthesizing the magnetic iron oxide support. The experiments revealed that with a doping amount of 7.5 wt%, a molar ratio of glucose/urea/iron of 5:20:8, and an ignition temperature of 400 °C, the NH₃-SCR activity of the novel catalyst could be optimized.

制备了一种新型的钨掺杂磁性氧化铁催化剂，用于通过NH ₃（NH ₃ -SCR）选择性催化还原NO _x，其由固溶燃烧合成的含碳磁性材料Fe ₂ O ₃ --H支撑然后氧化过氧化氢。其结果是，γ-Fe的热稳定性_2级ö ₃位于磁性支撑微晶被显著增强。同时，Fe ₂ O ₃的不可逆转变在高温（即400℃）下的退火过程中，从γ相到α相的微晶受到很大程度的抑制。另外，由于钨掺杂对磁性Fe ₂ O ₃的抗烧结作用，磁性W / Fe ₂ O ₃催化剂呈现出具有较高的BET表面积和孔体积的优良多孔结构。。在这方面，表面酸度以及表面吸附的氧的摩尔比大大增加，从而导致了催化剂中活性本体物质的氧化还原能力的显着提高。值得一提的是，催化剂中钨的掺杂量，葡萄糖/脲/铁的摩尔比以及合成磁性氧化铁载体的着火温度会影响热稳定性和氧化还原能力的提高。实验表明，掺杂量为7.5 wt％，葡萄糖/尿素/铁的摩尔比为5：20：8，且着火温度为400°C，该新型催化剂的NH ₃ -SCR活性为优化。