Topological Aspect of the Distribution of Co Species and N2O Decomposition Performance for Co/Zeolite Catalysts
Topological Aspect of the Distribution of Co Species and N2O Decomposition Performance for Co/Zeolite Catalysts
复制标题
DOI：
10.1021/acs.energyfuels.3c01958
复制
发表时间：
2023-07
期刊：
影响因子：
--
通讯作者：
Bin Kang;Runduo Zhang;Mengfei Guo;Xiaonan Guo;Zhaoying Di;Yingxi Wei;Jingbo Jia
中科院分区：
文献类型：
--
作者：
Bin Kang;Runduo Zhang;Mengfei Guo;Xiaonan Guo;Zhaoying Di;Yingxi Wei;Jingbo Jia
本研究制备了一系列具有不同微孔结构的Co/沸石催化剂，并将其应用于N2 O催化分解。催化剂活性的大小顺序为Co/Beta > Co/丝光沸石> Co/ZSM-5 > Co/MCM-49 > Co/ZSM-23 > Co/ZSM-35 > Co/SSZ-13，而副产物NO2的产率的大小顺序为Co/ZSM-23 > Co/ZSM-35 > Co/MCM-49 > Co/丝光沸石> Co/ZSM-5 > Co/Beta > Co/SSZ-13。在N2 O体积分数为30%，空速为30 000 h-1的条件下，最佳催化剂（Co/beta）在450 °C时的N2 O转化率为99.6%。此外，在Co/ZSM-23催化剂中，NO_2的生成量随Co/Beta催化剂浓度的变化而显著降低，其浓度从1063 ppm变化到82 ppm。通过XRD、BET、H2-TPR、NH3-TPD、XPS、UV-vis-DRS等物理化学手段对催化剂进行表征，发现具有较高孔径尺寸的沸石分子筛（12元环，12-MR）有利于Co离子通过孔道引入到沸石骨架上，并进一步定位在离子-交换位点形成活性中心（Co2+）。分子动力学模拟结果表明，沸石的孔径越大，越有利于N2 O在沸石孔道内的扩散，促进N2 O的分解。
In this study, series of Co/zeolites with diverse microporous structures were prepared and applied for N2O catalytic decomposition. The corresponding activities followed the order Co/Beta > Co/Mordenite > Co/ZSM-5 > Co/MCM-49 > Co/ZSM-23 > Co/ZSM-35 > Co/SSZ-13, while the yield of NO2byproduct followed the order Co/ZSM-23 > Co/ZSM-35 > Co/MCM-49 > Co/Mordenite > Co/ZSM-5 > Co/Beta > Co/SSZ-13. Under conditions of 30 vol % N2O and GHSV = 30 000 h–1, the best performing sample (Co/beta) achieved a remarkable N2O conversion of 99.6% at 450 °C. In addition, the formation of NO2byproduct was significantly inhibited with the corresponding concentration varying from 1063 ppm for Co/ZSM-23 to 82 ppm for Co/Beta. Physicochemical characterization of these as-prepared catalysts was performed including XRD, BET, H2-TPR, NH3-TPD, XPS, UV-vis-DRS, and it was found that zeolites with higher dimensionally porous apertures (3D) and larger pore sizes (12-membered ring, 12-MR) were conducive to introducing Co ions onto the zeolite framework through the pore channels and further locating them on ion-exchange sites to form active centers (Co2+). Furthermore, molecular dynamics simulation demonstrated that the higher pore dimensions and larger pore sizes are more beneficial for the N2O diffusion inside the pores and channels of zeolites and promote N2O decomposition.