### 不同晶型二氧化锰纳米棒催化氧化氯苯性能的研究

1. 武汉工程大学化工制药学院 绿色化工过程教育部重点实验室 武汉 430074
• 投稿日期:2012-08-18 发布日期:2012-10-18
• 通讯作者: 刘善堂 E-mail:liushantang@mail.wit.edu.cn
• 基金资助:
项目受国家自然科学基金(Nos. 20873097, 21071113)、湖北省自然科学基金(No. 2011CDA049)、武汉市学科带头人(No. 200951830551)和湖北省教育厅科学技术研究重大项目(No. Z20091502)资助.

### Catalytic Oxidation of Chlorobenzene over MnO2 Nanorods with Different Phase Structures

Li Jingwei, Song Can, Liu Shantang

1. Key Laboratory for Green Chemical Process of Ministry of Education, School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan 430074
• Received:2012-08-18 Published:2012-10-18
• Supported by:
Project supported by the National Natural Science Foundation of China (Nos. 20873097, 21071113), Natural Science Foundation of Hubei Province (No. 2011CDA049), Wuhan Municipal Scientific Leader Program (No. 200951830551) and Key Project of Hubei Provincial Department of Education (No. Z20091502)

Mn-containing catalysts are widely used owing to their excellent redox properties, while in most cases they would deactivate to some extent in the oxidation process of the chloride volatile organic compounds (CVOCs) due to chlorine poisoning. In this work α-, β-, γ-MnO2 nanorods were synthesized via a hydrothermal route, and their catalytic performance for chlorobenzene (CB, as a model of CVOCs) and resistance to chlorine poisoning were studied. The results showed that the MnO2 nanorods with different phase structures exhibited high activities for low temperature catalytic oxidation of CB, and the catalytic activities of the MnO2 nanorods depended on the crystal phase of MnO2, following in the order of α-MnO2γ-MnO2β-MnO2. Moreover, the MnO2 nanorods showed high resistance to chlorine poisoning compared to the amorphous MnO2. The experiment results indicated that the conversion of CB over α-, β-, γ-MnO2 nanorods at 250 ℃ remained stable at about 98%, 82% and 90% respectively for 35 h. Contrasted to MnO2 nanorods, the conversion of CB over amorphous MnO2 dropped from 80% to 32% in the same condition. Additionally, the as-synthesized MnO2 nanorods were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), H2 temperature-programmed reduction (H2-TPR) and X-ray photoelectron spectroscopy (XPS). XRD results showed that the crystallinity of α-, β-, γ-MnO2 nanorods were different, and decreased in the order: βαγ, implying that the crystallinity of α-, β-, γ-MnO2 nanorods had no significant effect on its catalytic performance. SEM and TEM showed that three kinds of nanorods were well dispersed, and exhibited one-dimensional nanorods. H2-TPR and XPS results demonstrated that the high catalytic activity of α-MnO2 nanorods resulted from their rich lattice oxygen and good reducibility. Therefore, the enrichment of the lattice oxygen with excellent reducibility was considered as main reason of high activity of α-MnO2 nanorods for low temperature catalytic destruction of CB.