Molecular dynamics (MD) simulation was carried out to investigate the diffusion behaviors of NH3 and flue gases on CeO2-TiO2 (CT) catalyst for the selective catalytic reduction of NO with NH3. The influence of temperature, gas mixtures, and slit width of catalyst on the diffusivity of the target molecules were studied. The results showed that both temperature and the competitive diffusion of the target molecules substantially impact gas diffusion within nano-slits. The NH3 diffusion was demonstrated to have heightened sensitivity to temperature fluctuations. SO2 showed the greatest hindering effect in all of five gases. The negative effect on NH3 diffusion was greater when H2O existed in the form of hydroxyl groups. Increasing the slit distance of catalyst significantly mitigated this effect, with a decrease in diffusion impedance from 32.51 % to 5.01 % as the distance expanded from 2.5 nm to 7.5 nm. As for NO, a similar suppressive effect was observed when mixed with SO2, but the influence of hydroxyl groups was notably less pronounced compared to NH3. Specifically, there was only a decrease of 15.14 % at a distance of 2.5 nm, followed by almost no decrease when the distance was increased to 7.5 nm.

中文翻译：

---

CeO2-TiO2 基 SCR 催化剂纳米孔中多污染物的传质特性：分子动力学研究


进行分子动力学 （MD） 模拟，研究 NH3 和烟气在 CeO2-TiO2 （CT） 催化剂上的扩散行为，以利用 NH3 选择性催化还原 NO。研究了温度、气体混合物和催化剂狭缝宽度对目标分子扩散率的影响。结果表明，温度和目标分子的竞争性扩散都会对纳米狭缝内的气体扩散产生重大影响。NH3 扩散被证明对温度波动具有更高的敏感性。SO2 在所有 5 种气体中均显示出最大的阻碍作用。当 H2O 以羟基形式存在时，对 NH3 扩散的负面影响更大。增加催化剂的狭缝距离显著减轻了这种影响，当距离从 2.5 nm 扩展到 7.5 nm 时，扩散阻抗从 32.51 % 降低到 5.01 %。至于 NO，与 SO2 混合时观察到类似的抑制效果，但与 NH3 相比，羟基的影响明显不那么明显。具体来说，在 2.5 nm 的距离处仅减少了 15.14%，随后当距离增加到 7.5 nm 时几乎没有减少。