Morphology-controlled synthesis and sulfur modification of 3D hierarchical layered double hydroxides for gaseous elemental mercury removal
Morphology-controlled synthesis and sulfur modification of 3D hierarchical layered double hydroxides for gaseous elemental mercury removal
复制标题
用于气态元素汞去除的 3D 分级层状双氢氧化物的形态控制合成和硫改性
DOI：
10.1016/j.jcis.2018.10.062
复制
发表时间：
2019
影响因子：
9.9
通讯作者：
Yan Naigiang
中科院分区：
文献类型：
--
作者：
Yuan Yong;Xu Haomiao;Liu Wei;Chen Lihong;Quan Zongwen;Liu Ping;Qu Zan;Yan Naigiang
多孔结构和有效活性位有利于气态元素汞（Hg 0）的捕集。采用原位生长法合成了两种多级孔层状双金属氢氧化物（LDHs）。硫被用于这些LDHs的改性，以提高除汞性能。结果表明，两种NiAl-S4@ SiO2微球均为三维形貌，分别为核壳结构和海胆结构。采用XRD、BET、FTIR、TEM和SEM等测试手段研究了结构对吸附Hg 0的影响。结果表明，S改性后，Hg 0去除率提高，抗SO2能力增强。在100 °C时，除汞性能的顺序为：NiAl-S4@SiO2-海胆> NiAl-S4@SiO2-芯。结合TPD、EDX和XPS等测试结果，对脱汞机理进行了探讨。NiAl-S4@ SiO2复合材料的多孔结构有利于气体转化，插层的[S4]2−离子有利于汞的吸收。多硫化物与吸附的汞结合形成HgS。这种材料具有从S单键汞混合烟气中吸收汞的潜力。
Porous structure and effective active site are beneficial for gaseous elemental mercury (Hg0) capture. Two kinds of hierarchical porous layered double hydroxides (LDHs) were synthesized through an in-situ growth method. Sulfur was used for the modification of these LDHs to enhance Hg0removal performance. Two as-prepared NiAl-S4@SiO2microspheres displayed three-dimensional morphologies, accordingly exhibited as core-shell and urchin-like morphologies. XRD, BET, FTIR, TEM and SEM were employed to investigate the structure effect on Hg0uptake. The results indicated that after S-modification, the Hg0removal efficiencies as well as SO2resistance were enhanced. The Hg0removal performances follow the order of: NiAl-S4@SiO2-urchin > NiAl-S4@SiO2-core at 100 °C. The mechanism for Hg0removal was discussed based on the results of TPD, EDX and XPS. The porous structure of NiAl-S4@SiO2composite was beneficial for gas transformation and intercalated [S4]2−ions were favorable for mercury uptake. The polysulfide combined with adsorbed mercury and formed HgS. Such materials exhibit promising potential for mercury uptake from Ssingle bondHg mixed flue gas.