A series of vanadium doped Fe₂O₃ catalysts were synthesized using the homogeneous precipitation method and subjected to laboratory evaluation for selective catalytic reduction of NO_x with NH₃ (NH₃-SCR). The best Fe_0.75V_0.25O_δ catalyst with a Fe/V mole ratio of 3/1 exhibited superior catalytic performance, achieving 100% NO_x conversion at 200 °C over a wide temperature window from 175 to 400 °C, believed to be the best Fe-based low-temperature NH₃-SCR catalyst identified to date. The Fe_0.75V_0.25O_δ catalyst also showed prominent resistance to high gas hourly space velocity (GHSV; 200 000 h^–1) and strong durability to SO₂ and H₂O. Doping of V was shown to remarkably boost the catalytic activity, due to enhancement of the redox ability and surface acidity. XRD, Raman, and morphology results revealed that the incorporation of V had led to the formation of amorphous FeVO₄ and Fe₂O₃. Coupling XPS and UV–vis diffuse reflectance spectra (DRS) results with DFT, it was discovered that the electron inductive effect between Fe and V generated the charge depletion of Fe, resulting in an improvement of the redox ability, facilitating the oxidation of NO to NO₂. Meanwhile, the strong interaction between FeVO₄ and Fe₂O₃ species kept V at a higher valence, beneficial for the adsorption and activation of NH₃. The synergistic effect of FeVO₄ and Fe₂O₃ thus improved the low-temperature catalytic activity and lowered the apparent activation energy. Combining in situ diffusion Fourier transform infrared spectroscopy (DRIFTS) results with reaction kinetic studies, it was concluded that the SCR reaction mainly followed the Langmuir–Hinshelwood mechanism below 200 °C, since the consumption of adsorbed NH₃ species could be divided into the explicit “standard SCR” and “fast SCR” stages, while an Eley–Rideal mechanism proceeded dominantly at and above 200 °C, in which the adsorbed NH₃ species were eliminated by gaseous NO directly and linearly. Both the Brønsted and Lewis acid sites played equivalently significant roles in NH₃-SCR reaction.

中文翻译：

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诱导效应推进高级的Fe催化性能_1个-x V _X ø _δ催化剂在低温NH ₃选择性催化还原：洞察结构，交互和机制

一系列钒掺杂的Fe ₂ ö _3个催化剂使用均匀沉淀法合成，并进行实验室评估用于选择性催化还原的NO _X与NH ₃（NH ₃ -SCR）。最好的Fe _0.75 V _0.25 ø _δ与3/1由Fe / V摩尔比的催化剂显示出优异的催化性能，实现100％的NO _X在200℃下在宽的温度窗口从175℃至400℃转化率，认为是迄今为止确定的最佳铁基低温NH ₃ -SCR催化剂。中的Fe _0.75 V _0.25 ö _δ催化剂还显示出对高气体时空速度（GHSV; 200 000 h ^–1）的显着抵抗力，以及对SO ₂和H ₂ O的强耐久性。由于提高了氧化还原能力，掺杂V可以显着提高催化活性。和表面酸度。XRD，拉曼和形态学结果表明，V的引入导致非晶态的FeVO ₄和Fe ₂ O _3的形成。将XPS和UV-vis漫反射光谱（DRS）结果与DFT耦合，发现Fe和V之间的电子感应效应产生了Fe的电荷耗尽，从而提高了氧化还原能力，促进了NO氧化为NO ₂。同时，FeVO ₄和Fe ₂ O ₃之间的强相互作用使V保持较高的价态，有利于NH ₃的吸附和活化。FeVO ₄和Fe ₂ O ₃的协同作用因此改善了低温催化活性并降低了表观活化能。将原位扩散傅里叶变换红外光谱（DRIFTS）结果与反应动力学研究相结合，得出的结论是，SCR反应主要遵循200°C以下的Langmuir-Hinshelwood机理，因为吸收了NH ₃物种可分为明确的“标准SCR”和“快速SCR”阶段，而Eley-Rideal机理主要在200°C和更高温度下进行，其中被气态NO直接和线性地消除了吸附的NH ₃物种。布朗斯台德和路易斯酸位在NH ₃ -SCR反应中均起着相当重要的作用。