Insight into the role of ceria on OMS-2 and OL materials for catalytic degradation of toluene
Insight into the role of ceria on OMS-2 and OL materials for catalytic degradation of toluene
复制标题
深入了解二氧化铈对 OMS-2 和 OL 材料催化降解甲苯的作用
DOI：
10.3389/fenvc.2020.599349
复制
发表时间：
2020
影响因子：
--
通讯作者：
Chi He
中科院分区：
文献类型：
--
作者：
Lin Yue;Minghua Hu;Mingjiao Tian;Xu Liao;Zhihua Xu;Ling Shi;Chi He
催化氧化法是去除工业挥发性有机物的有效方法之一。MnOx基催化剂因其优异的低温催化活性而备受关注。本文采用回流法合成了层间距为7 μ m的八面体层状水钠锰矿型锰氧化物（OL-1）和隧道孔径为4.6 × 4.6 μ m的锰钾矿型锰氧化物（OMS-2）。在此基础上，以提高甲苯氧化催化性能为目标，采用浸渍法制备了Ce掺杂的OL-1和OMS-2催化剂。结果表明，OMS-2材料由于含有大量的活性晶格氧物种，在224 °C时甲苯的分解率可达90%以上，表现出最佳的催化活性。有趣的是，Ce的引入导致大量酸性中心的形成，从而限制了氧化过程并提高了苯甲酸副产物的产率。
Catalytic oxidation is one of the most efficient approaches for industrial volatile organic compounds (VOCs) elimination. MnOx-based catalysts have attracted much attention due to their remarkable low-temperature catalytic activity. Herein, octahedral layered birnessite-type manganese oxide (OL-1) with layer spacing of 7 Å and cryptomelane type manganese oxide (OMS-2) with tunneled pore diameter of 4.6 × 4.6 Å were synthesized by a reflux method. Following this, Ce-doped OL-1 and OMS-2 were further prepared by an impregnation method with target to improve catalytic performance in toluene oxidation. Results reveal that the OMS-2 material exhibits the best catalytic activity with 90% of toluene decomposed at 224 °C owing to the presence of a large quantity of active lattice oxygen species. Interestingly, the introduction of Ce leads to the formation of large amounts of acidic sites, which limit the oxidation process and enhance the yield of benzoic acid by-product.