State Key Laboratory for Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, China.
POWERCHINA Central China Electric Power Engineering Co., Ltd., Zhengzhou, 450007, China.
Environ Sci Pollut Res Int. 2022 Jan;29(5):7042-7052. doi: 10.1007/s11356-021-15477-y. Epub 2021 Aug 31.
The high toxicity and low volatility of PCDD/Fs prevent detailed study of their catalytic degradation removal characteristics. In this study, 1,2-dichlorobenzene (1,2-DCBz) was initially used as a model to investigate the catalytic characteristics of various vanadium-based catalysts prepared by different methods. Then, the optimized catalyst was used for catalytic degradation of real PCDD/Fs at low temperatures based on a self-made stable source. The VO/TiO catalysts synthesized by the mechanochemical method (VTi-MC2) had a higher 1,2-DCBz removal efficiency (>85%) and stability (> 420 min) at low temperatures (< 200 °C) compared to VTi-SG (sol-gol method) and VTi-WI (wetness impregnation method). The physicochemical properties of catalysts were studied using comprehensive characterization. It was found that the VTi-MC2 has better VO species distribution and possesses the highest V species and surface adsorbed oxygen content, which are the key factors that contributed to the higher removal efficiency. Accordingly, the mechanochemical method can be used to control the physicochemical properties of catalysts by adjusting the milling parameters. The optimum ball milling time is 2 h and a suitable precursor is NHVO for VO/TiO. Moreover, the removal efficiency and catalytic degradation efficiency of PCDD/Fs in gas phase catalyzed by VTi-MC2 were 97% and 50% respectively, within a range of temperatures below 200 °C, which are both higher than those reported research. In general, the mechanochemical strategy employed in this study provides a means for seeking more efficient catalysts used for low-temperature degradation of various trace organic pollutants.
PCDD/Fs 的高毒性和低挥发性阻碍了对其催化降解去除特性的详细研究。在本研究中，首先使用 1,2-二氯苯（1,2-DCBz）作为模型，研究了通过不同方法制备的各种钒基催化剂的催化特性。然后，基于自制的稳定源，在低温下使用优化的催化剂对实际 PCDD/Fs 进行催化降解。与 VTi-SG（溶胶-凝胶法）和 VTi-WI（湿浸渍法）相比，机械化学法（VTi-MC2）合成的 VO/TiO 催化剂在低温（<200°C）下具有更高的 1,2-DCBz 去除效率（>85%）和稳定性（>420min）。通过综合表征研究了催化剂的物理化学性质。结果发现，VTi-MC2 具有更好的 VO 物种分布，并且具有最高的 V 物种和表面吸附氧含量，这是导致更高去除效率的关键因素。因此，机械化学方法可以通过调整研磨参数来控制催化剂的物理化学性质。最佳球磨时间为 2h，合适的前体为 NHVO 用于制备 VO/TiO。此外，在 200°C 以下的温度范围内，VTi-MC2 催化气相中 PCDD/Fs 的去除效率和催化降解效率分别为 97%和 50%，均高于已报道的研究结果。总的来说，本研究中采用的机械化学策略为寻找更高效的催化剂用于各种痕量有机污染物的低温降解提供了一种手段。
