Catalytic removal of gaseous unintentional POPs on manganese oxide octahedral molecular sieves
Catalytic removal of gaseous unintentional POPs on manganese oxide octahedral molecular sieves
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DOI：
10.1016/j.apcatb.2013.05.048
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发表时间：
2013-10
影响因子：
22.1
通讯作者：
Yang Yang-Yang;Jun Huang;Siwen Wang;S. Deng;Bin Wang;Gang Yu
中科院分区：
文献类型：
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作者：
Yang Yang-Yang;Jun Huang;Siwen Wang;S. Deng;Bin Wang;Gang Yu
六氯苯（HCBz）、五氯苯（PeCBz）和多氯联苯（PCB）是燃烧和工业过程中无意排放的持久性有机污染物。采用α-、β-、γ-和δ-MnO 2四种晶体结构的氧化锰八面体分子筛（OMS）对气态六氯苯进行催化去除。与V2 O 5基催化剂相比，所有OMS催化剂在高空速（660，000 h-1）下都表现出高活性。OMS的催化性能依次为δ- > α- > γ- > β-MnO 2。结果表明，吸附和破坏过程都会影响去除效率。前者与催化剂的比表面积、孔体积（3.3- 6.4nm）和表面酸中心呈正相关，而后者与催化剂的还原度和表面不稳定氧的量有关。性能最好的δ-MnO 2被进一步用于销毁痕量浓度（305 μg N m−3）的气态PeCBz、HCBz和PCB混合物。在230 °C和132，000 h-1的空速下实现了高RE（99.3%）。
Hexachlorobenzene (HCBz), pentachlorobenzene (PeCBz), and polychlorinated biphenyls (PCBs) are persistent organic pollutants emitted unintentionally from combustion and industrial processes. Catalytic removal of gaseous HCBz was achieved using manganese oxide octahedral molecular sieve (OMS) in four crystal structures: α-, β-, γ- and δ-MnO2. All OMS catalysts present high activity at high space velocity (660,000 h−1) in comparison to V2O5based catalyst. The catalytic performance of OMS decreases in the order of δ- > α- > γ- > β-MnO2. It is found that both adsorption and destruction processes influence the removal efficiency (RE). The former is positively correlated with surface area, pore (3.3–6.4 nm) volume, and surface acid sites, while the latter is coherent with both catalyst reducibility and the amount of surface labile oxygen. The best-performing δ-MnO2was further applied for the destruction of gaseous PeCBz, HCBz, and PCB mixture at trace concentration (305 μg N m−3). High RE (99.3%) was achieved at 230 °C with the space velocity of 132,000 h−1.