Low-temperature catalytic oxidative coupling of methane in an electric field over a Ce-W-O catalyst system.
Low-temperature catalytic oxidative coupling of methane in an electric field over a Ce-W-O catalyst system.
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DOI：
10.1038/srep25154
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发表时间：
2016-04-27
影响因子：
4.6
通讯作者：
Sekine Y
中科院分区：
文献类型：
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作者：
Sugiura K;Ogo S;Iwasaki K;Yabe T;Sekine Y
在423 K的电场条件下，研究了不同Ce-W-O催化剂对甲烷（OCM）氧化偶联的影响。Ce2(WO4)3/CeO2催化剂具有较高的OCM活性。在Ce2(WO4)3/CeO2催化剂上进行的周期性运行试验中，在3个氧化还原循环中，C2选择性超过60%。而没有电场的Ce2(WO4)3/CeO2催化剂即使在1073 K: CH4转化率为6.0%时也表现出较低的活性；C2选取。, 2.1%。Ce2(WO4)3结构与电场之间的协同作用产生了选择性氧化甲烷的活性氧。XAFS、原位拉曼和周期性运行测试结果表明，OCM的发生是由于Ce2(WO4)3中的晶格氧（扭曲WO4单元中的短W-O键）被消耗。消耗的氧在电场中通过氧化还原机制再生。
We examined oxidative coupling of methane (OCM) over various Ce–W–O catalysts at 423 K in an electric field. Ce2(WO4)3/CeO2 catalyst showed high OCM activity. In a periodic operation test over Ce2(WO4)3/CeO2 catalyst, C2 selectivity exceeded 60% during three redox cycles. However, Ce2(WO4)3/CeO2 catalyst without the electric field showed low activity, even at 1073 K: CH4 Conv., 6.0%; C2 Sel., 2.1%. A synergetic effect between the Ce2(WO4)3 structure and electric field created the reactive oxygen species for selective oxidation of methane. Results of XAFS, in-situ Raman and periodic operation tests demonstrated that OCM occurred as the lattice oxygen in Ce2(WO4)3 (short W–O bonds in distorted WO4 unit) was consumed. The consumed oxygen was reproduced by a redox mechanism in the electric field.