Li Ping, Lu Pei, Zhai Yunbo, Li Caiting, Chen Ting, Qing Renpeng, Zhang Wei
a College of Environmental Science and Engineering , Hunan University , Changsha 410082 , People's Republic of China.
Environ Technol. 2015;36(18):2390-400. doi: 10.1080/09593330.2015.1031829. Epub 2015 Apr 16.
Achievement of a higher NOx conversion ratio in selective catalytic reduction (SCR) at low temperature is challenging. In this work, pure activated carbon fibres (ACFs) were modified with different ratios of H2O (g), NaOH, CO2 and HNO3, respectively (named as modified ACF). The chemical and physical properties of modified ACFs were identified by Brunauer-Emmett-Teller, X-ray diffraction, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy methods. The NOx conversion ratio of ACF was improved from 56.1% to 82.4% at 80°C after modification with 30% (mass ratio) NaOH. These modified ACFs were further loaded with the mixture of MnO2 and CeO2 in the form of metal salt solutions (named as Mn0.5Ce0.5O2/modified ACF). The NOx conversion ratio of 30% SHACF remained similar at 80°C but was increased from 60.0% to 98.5% at 360°C after loading with Mn and Ce, which showed the best performance in SCR of NOx at low temperature. It could be seen that ACF delivered higher performance in low temperature SCR after being modified with the aforementioned reactants and further loading with metals. Based on chemical and physical characterization and the performance of the catalysts, the reasons for different performances of these catalysts in low temperature SCR are discussed.
在低温下的选择性催化还原（SCR）中实现更高的氮氧化物转化率具有挑战性。在这项工作中，分别用不同比例的H₂O（g）、NaOH、CO₂和HNO₃对纯活性炭纤维（ACF）进行改性（命名为改性ACF）。通过布鲁诺尔-埃米特-泰勒法、X射线衍射法、傅里叶变换红外光谱法和X射线光电子能谱法对改性ACF的化学和物理性质进行了鉴定。用30%（质量比）的NaOH改性后，ACF在80°C时的氮氧化物转化率从56.1%提高到了82.4%。这些改性ACF进一步负载了MnO₂和CeO₂的金属盐溶液混合物（命名为Mn₀.₅Ce₀.₅O₂/改性ACF）。30%SHACF在80°C时的氮氧化物转化率保持相似，但负载Mn和Ce后在360°C时从60.0%提高到了98.5%，这表明其在低温SCR脱硝中表现最佳。可以看出，ACF在经过上述反应物改性并进一步负载金属后，在低温SCR中表现出更高的性能。基于化学和物理表征以及催化剂的性能，讨论了这些催化剂在低温SCR中表现不同的原因。
