Zheng Siyi, Song Lei, Tang Siyang, Liu Changjun, Yue Hairong, Liang Bin
Multi-phases Mass Transfer and Reaction Engineering Laboratory, School of Chemical Engineering, Sichuan University Chengdu 610065 China
Institute of New Energy and Low-Carbon Technology, Sichuan University Chengdu 610207 China.
RSC Adv. 2018 Jan 9;8(4):1979-1986. doi: 10.1039/c7ra11868f. eCollection 2018 Jan 5.
The rational synthesis of low-temperature catalysts with high catalytic activity and stability is highly desirable for the selective catalytic reduction of NO with NH. Here we synthesized a Mn-SiO/TiO nano-cup catalyst the coating of the mesoporous TiO layers on SiO spheres and subsequent inlay of MnO nanoparticles in the narrow annulus. This catalyst exhibited superior catalytic SCR activities and stability for low-temperature selective catalytic reduction of NO with NH, with NO conversion of ∼100%, N selectivity above 90% at a temperature ∼140 °C. The characterization results, such as BET, XRD, H-TPR, O/NH-TPD and XPS, indicated that this nano-cup structure catalyst possesses high concentration and dispersion of Mn active species, strong chemisorbed O or O species and highly stable MnO active components over the annular structures of the TiO shell and SiO sphere, and thus enhanced the low-temperature SCR performance.
对于用NH₃选择性催化还原NO而言，合理合成具有高催化活性和稳定性的低温催化剂是非常有必要的。在此，我们合成了一种Mn-SiO₂/TiO₂纳米杯催化剂，即在SiO₂球上包覆介孔TiO₂层，随后在狭窄的环隙中镶嵌MnO₂纳米颗粒。该催化剂在低温下用NH₃选择性催化还原NO时表现出优异的催化SCR活性和稳定性，在约140℃时，NO转化率约为100%，N₂选择性高于90%。BET、XRD、H₂-TPR、O₂/NH₃-TPD和XPS等表征结果表明，这种纳米杯结构催化剂在TiO₂壳层和SiO₂球的环形结构上具有高浓度和高分散性的Mn活性物种、强化学吸附的O或O₂物种以及高度稳定的MnO₂活性组分，从而提高了低温SCR性能。
