Catalytic oxidation of dibromomethane over Ti-modified Co3O4 catalysts: Structure, activity and mechanism
Catalytic oxidation of dibromomethane over Ti-modified Co3O4 catalysts: Structure, activity and mechanism
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Ti 改性 Co3O4 催化剂催化氧化二溴甲烷：结构、活性和机理
DOI：
10.1016/j.jcis.2017.06.077
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发表时间：
2017-11-01
影响因子：
9.9
通讯作者：
Yan, Naiqiang
中科院分区：
文献类型：
--
作者：
Mei, Jian;Huang, Wenjun;Yan, Naiqiang
使用共沉淀方法合成具有各种CO/TI比的TI修饰CO3O4催化剂，并用于二溴甲烷（CH2BR2）的催化氧化，该催化氧化为溴化伏挥发性有机化合物（BVOCS）的模型分子。 Ti的添加使晶体结构变形，并导致了Co-O-Ti固体溶液的形成。 CO4TI1（CO/Ti摩尔比为4），用焦油（90％转化所需的温度）用于CH2BR2氧化约245摄氏度，在低温下对CO2的催化活性高于其他研究的催化剂。此外，CO4TI1至少30帽子500 ppm CH2BR2，0或2 Vol％H2O，0或500 ppm ppm p-xylene（PX）和10％O-O-2在气体小时空间速度为60,000 h（ - 1）。最终产品是Cox，BR-2和HBR，没有其他含有BR的有机副产品的形成。高催化活性归因于高CO3+/CO2+比率和高表面酸度。另外，CO和Ti的协同作用使其对CH2BR2氧化具有优越性。此外，基于对产物和原位漂移研究的分析，提出了在TI改性CO3O4催化剂上进行CH2BR2氧化的应收反应机制。 （c）2017 Elsevier Inc.保留所有权利。
Ti-modified Co3O4 catalysts with various Co/Ti ratios were synthesized using the co-precipitation method and were used in catalytic oxidation of dibromomethane (CH2Br2), which was selected as the model molecule for brominated volatile organic compounds (BVOCs). Addition of Ti distorted the crystal structure and led to the formation of a Co-O-Ti solid solution. Co4Ti1 (Co/Ti molar ratio was 4) achieved higher catalytic activity with a Tar (the temperature needed for 90% conversion) of approximately 245 degrees C for CH2Br2 oxidation and higher selectivity to CO2 at a low temperature than the other investigated catalysts. In addition, Co4Ti1 was stable for at least 30 hat 500 ppm CH2Br2, 0 or 2 vol% H2O, 0 or 500 ppm p-xylene (PX), and 10% O-2 at a gas hourly space velocity of 60,000 h(-1). The final products were COx, Br-2, and HBr, without the formation of other Br-containing organic byproducts. The high catalytic activity was attributed to the high Co3+/Co2+ ratio and high surface acidity. Additionally, the synergistic effect of Co and Ti made it superior for CH2Br2 oxidation. Furthermore, based on the analysis of products and in situ DRIFTs studies, a receivable reaction mechanism for CH2Br2 oxidation over Ti-modified Co3O4 catalysts was proposed. (C) 2017 Elsevier Inc. All rights reserved.