Phase structures, morphologies, and NO catalytic oxidation activities of single-phase MnO2 catalysts
Phase structures, morphologies, and NO catalytic oxidation activities of single-phase MnO2 catalysts
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DOI：
10.1016/j.apcata.2016.01.005
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发表时间：
2016-03
影响因子：
5.5
通讯作者：
Baohuai Zhao;Rui Ran;Xiaodong Wu;D. Weng
中科院分区：
文献类型：
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作者：
Baohuai Zhao;Rui Ran;Xiaodong Wu;D. Weng
考察了单相α-，β-，γ-和δ-MnO2对NO的催化氧化活性。采用多种技术对催化剂进行了系统的表征。结果表明，催化剂的活性受MnO2相结构的影响较大。在四种催化剂中，海胆状γ-MnO2在研究的温度范围内表现出最好的NO催化氧化活性，在280℃时，NO转化率最高，为88%，即使与贵金属基催化剂相比，也是良好的活性。在较长的反应时间内也表现出最好的活性。其他三种催化剂的NO催化氧化活性按α-β>；δ-MnO2的顺序递减。MnO_2的各种相结构都含有相同的[MnO_6]八面体单元，但具有不同的连接方式。γ-MnO2具有无序结构，活性氧物种较多，具有较好的催化性能。
The NO catalytic oxidation activities of single-phase α-, β-, γ-, and δ-MnO2were investigated. All the catalysts were systematically characterized using various techniques. The results showed that the catalytic activities were significantly affected by the MnO2phase structures. Among the four catalysts, the urchin-like γ-MnO2showed the best NO catalytic oxidation activity across the studied temperature range, with the largest NO conversion, namely 88%, at 280 °C. This is good activity, even compared with those of noble-metal-based catalysts. It also displayed the best activity during long reaction times. The NO catalytic oxidation activities of the other three catalysts decreased in the order α- > β- > δ-MnO2. The various phase structures of MnO2contain the same [MnO6] octahedral units, but with different linking modes. γ-MnO2has a disordered structure, resulting in larger numbers of active oxygen species, leading to a better catalytic performance.