State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
J Environ Sci (China). 2020 Aug;94:32-39. doi: 10.1016/j.jes.2020.02.029. Epub 2020 Apr 16.
The surface species formed in the reaction of NO and NO with pre-adsorbed NH over a Fe-ZSM-5 catalyst (1.27 wt.% Fe, SiO/AlO = 25) at low temperature (140°C) were studied by in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Through using a background spectrum of NH-saturated Fe-ZSM-5, we clearly observed the formation of common intermediates resulting from the reaction of NO or NO + O with pre-adsorbed NH. This presents strong evidence that the oxidation of NO to form surface nitrates and nitrites is the key step for standard SCR at low temperature. In addition, the results suggest that in the SCR reaction at low temperature, the NH ions absorbed on Brønsted acid sites are less active than NH adsorbed on Lewis acid sites related to Fe species.
采用原位漫反射红外傅里叶变换光谱（DRIFTS）技术研究了低温（140°C）下，NO 和 NO 与预吸附 NH 在 Fe-ZSM-5 催化剂（1.27wt.%Fe，SiO/AlO=25）上反应生成的表面物种。通过使用 NH 饱和的 Fe-ZSM-5 的背景光谱，我们清楚地观察到了由 NO 或 NO+O 与预吸附 NH 反应生成常见中间体的形成。这有力地证明了 NO 氧化生成表面硝酸盐和亚硝酸盐是低温下标准 SCR 的关键步骤。此外，结果表明，在低温 SCR 反应中，吸附在 Brønsted 酸位上的 NH 离子的活性低于与 Fe 物种相关的 Lewis 酸位上吸附的 NH。
