Catalytic Decomposition of N2O at Low Temperature by Reduced Cobalt Oxides.
Catalytic Decomposition of N2O at Low Temperature by Reduced Cobalt Oxides.
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DOI：
10.1166/jnn.2016.11026
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发表时间：
2016-05
影响因子：
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通讯作者：
W. Eom;M. Ayoub;K. Yoo
中科院分区：
文献类型：
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作者：
W. Eom;M. Ayoub;K. Yoo
随后制备各种形式的氧化钴（Co3O4和Co2O3），并在稳态条件下在固定床微分反应器中在低温下测试N2O的分解。这些不同类型的氧化物通过沉淀法（PM）和通过煅烧市售的CoCO3来制备。还测试了市售钴氧化物Co3 O4和Co2 O3在不同温度下的N2O分解。发现所有类型的制备的和市售的钴氧化物在低于300 ℃的温度下在氧气存在下对N2O分解无活性。类似的不满意的结果，发现在低温N2O分解后浸渍的碱金属（10%Na）和碱土金属（10%Ba）在Co3O4。然后将这些催化剂在还原介质（H2气体）下还原。结果表明，钴氧化物催化剂还原后，在低温、氧气存在下，对N_2O的分解反应具有短时间的活性。还原形式的Co3O4催化剂显示出巨大的效率，即，在相同条件下，温度（300 ℃）为98%。从结果看，Co3O4本身似乎对N2O分解没有活性，但由于在还原过程中Co3O4的氧化态变化，其还原形式对该反应具有高度活性。
Various forms of cobalt oxide (Co3O4 and C0203) were subsequently prepared and tested for decomposition of N2O at low temperature in a fix bed differential reactor at steady state conditions. These different types of oxides were prepared by precipitation method (PM) and by calcination of commercially available CoCO3. Commercially available cobalt oxides C03O4 and C02O3 were also tested for N2O decomposition at different temperatures. All types of prepared and commercially available cobalt oxide were found inactive for N2O decomposition in the presence of oxygen at temperature less than 300 degrees C. Similar unsatisfactory results were found at low temperature N2O decomposition after impregnation of alkali metal (10% Na) and alkaline earth metal (10% Ba) over Co3O4. These catalysts were then reduced under reduction media (H2 gas). It was found that after reduction cobalt oxide catalysts became active for N2O decomposition for short time in the presence of oxygen at low temperature. The reduced form of Co3O4 catalyst showed enormous efficiency i.e., 98% at temperature (300 degrees C) under the same conditions. From results it seems that Co3O4 itself is not active for N2O decomposition but its reduced form is highly active for this reaction due to oxidation state change of C03O4 during reduction process.