College of Quality & Safety Engineering, China Jiliang University, Hangzhou, 310018, China.
Environ Sci Pollut Res Int. 2024 Feb;31(7):11276-11284. doi: 10.1007/s11356-024-31881-6. Epub 2024 Jan 13.
In this study, we synthesized a Ce-modified Mn/HZSM-5 adsorbent via the ultrasound-assisted impregnation for Hg capture. Given the addition of 15% CeO, ~ 100% Hg efficiency was reached at 200 °C, suggesting its promotional effect on Hg removal. The doped Ce introduced additional chemisorbed oxygen species onto the adsorbent surfaces, which facilitated the oxidation of Hg to HgO. Even though adding CeO led to a weakened adsorbent acidity, yet it appeared that this negative affect could be completely overcome by the enhanced oxidative ability, which finally endowed Ce-modified Mn/HZSM-5 with a satisfactory Hg removal performance within the whole investigated temperature range. During the Hg capture process, chemisorption was predominant with Mnoperating as the main active site for oxidizing Hg to Hg. Finally, the 15Ce-Mn/HZSM-5 adsorbent exhibited good recyclability and stability. However, its tolerance to HO and SO appeared relatively weak, suggesting that some modification should be conducted to improve its practicality.
在这项研究中，我们通过超声辅助浸渍法合成了一种 Ce 改性的 Mn/HZSM-5 吸附剂，用于 Hg 的捕获。在添加 15%CeO 的情况下，在 200°C 时达到了约 100%的 Hg 去除效率，表明其对 Hg 去除具有促进作用。掺杂的 Ce 在吸附剂表面引入了额外的化学吸附氧物种，促进了 Hg 向 HgO 的氧化。尽管添加 CeO 导致吸附剂酸度减弱，但似乎这种负面影响可以完全被增强的氧化能力所克服，最终使 Ce 改性的 Mn/HZSM-5 在整个研究温度范围内具有令人满意的 Hg 去除性能。在 Hg 捕获过程中，化学吸附占主导地位，Mn 作为将 Hg 氧化为 Hg 的主要活性位。最后，15Ce-Mn/HZSM-5 吸附剂表现出良好的可循环性和稳定性。然而，其对 HO 和 SO 的耐受性相对较弱，表明需要进行一些改进以提高其实用性。
