Lin Bo, Wang Aiyong, Guo Yanglong, Ding Yuanqing, Guo Yun, Wang Li, Zhan Wangcheng, Gao Feng
Key Laboratory for Advanced Materials, Research Institute of Industrial Catalysis, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, PR China.
Institute for Integrated Catalysis, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99352, United States.
ACS Omega. 2019 May 31;4(5):9542-9551. doi: 10.1021/acsomega.9b00763.
Co-, Ni-, and Zn-containing MOFs are prepared and then pyrolyzed to generate materials for ambient temperature NO adsorption. Materials containing Co are much more efficient for NO adsorption than those containing Ni and Zn; therefore, Co is identified as the active phase. The best performing material studied here achieves 100% low concentration (10 ppm) NO adsorption for more than 15 h under a weight hourly space velocity of 120 000 mL g h. Powder X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared, and Raman spectroscopies, along with scanning electron microscopy and TEM, are used to probe the physicochemical properties of the materials, particularly the Co active phase, and chemistries involved in NO adsorption-desorption. NO adsorbs on oxygen-covered Co nanoparticle surfaces in the form of nitrates and desorbs as NO at higher temperatures as a result of surface nitrate decomposition. NO storage capacity decreases gradually upon repeated NO adsorption-desorption cycles, likely because of CoO formation during these processes.
制备了含钴、镍和锌的金属有机框架材料（MOFs），然后进行热解以生成用于常温NO吸附的材料。含钴材料对NO的吸附效率远高于含镍和锌的材料；因此，钴被确定为活性相。在此研究的性能最佳的材料在120 000 mL g⁻¹ h⁻¹的重量空速下，对10 ppm的低浓度NO吸附超过15小时，吸附率达到100%。利用粉末X射线衍射、X射线光电子能谱、傅里叶变换红外光谱和拉曼光谱，以及扫描电子显微镜和透射电子显微镜来探究材料的物理化学性质，特别是钴活性相以及NO吸附 - 解吸过程中涉及的化学性质。NO以硝酸盐的形式吸附在被氧覆盖的钴纳米颗粒表面，并在较高温度下由于表面硝酸盐分解而以NO的形式解吸。在反复的NO吸附 - 解吸循环中，NO存储容量逐渐降低，这可能是由于在这些过程中形成了CoO。
