Catalytic Oxidation of Methane into Methanol over Copper-Exchanged Zeolites with Oxygen at Low Temperature.
Catalytic Oxidation of Methane into Methanol over Copper-Exchanged Zeolites with Oxygen at Low Temperature.
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DOI：
10.1021/acscentsci.6b00139
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发表时间：
2016-06-22
影响因子：
18.2
通讯作者：
Román-Leshkov Y
中科院分区：
文献类型：
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作者：
Narsimhan K;Iyoki K;Dinh K;Román-Leshkov Y
在低温下使用分子氧将甲烷直接催化转化为液体含氧化合物，如甲醇或二甲醚，是C-H活化中的巨大挑战，这在合成的非均相催化剂中从未遇到过。我们报告的第一个演示的直接，催化氧化甲烷成甲醇的分子氧在铜交换沸石在低反应温度（483-498 K）。反应动力学研究表明，在温和条件下（例如，483 K和大气压）。瞬态和稳态测量同位素标记的分子确认催化营业额。催化速率和表观活化能受沸石拓扑结构的影响，笼型沸石（例如，Cu-SSZ-13）显示出最高的速率。虽然反应速率较低，但铜交换沸石中催化位点的发现将加速在温和条件下将甲烷直接氧化成甲醇的策略的发展。铜交换沸石（例如，MFI、莫尔和CHA）催化甲烷在气相中、在低温下并且仅使用分子氧和水直接氧化成甲醇。
The direct catalytic conversion of methane to liquid oxygenated compounds, such as methanol or dimethyl ether, at low temperature using molecular oxygen is a grand challenge in C–H activation that has never been met with synthetic, heterogeneous catalysts. We report the first demonstration of direct, catalytic oxidation of methane into methanol with molecular oxygen over copper-exchanged zeolites at low reaction temperatures (483–498 K). Reaction kinetics studies show sustained catalytic activity and high selectivity for a variety of commercially available zeolite topologies under mild conditions (e.g., 483 K and atmospheric pressure). Transient and steady state measurements with isotopically labeled molecules confirm catalytic turnover. The catalytic rates and apparent activation energies are affected by the zeolite topology, with caged-based zeolites (e.g., Cu-SSZ-13) showing the highest rates. Although the reaction rates are low, the discovery of catalytic sites in copper-exchanged zeolites will accelerate the development of strategies to directly oxidize methane into methanol under mild conditions. Copper-exchanged zeolites (e.g., MFI, MOR, and CHA) catalyze the direct oxidation of methane into methanol in the gas phase, at low temperature, and using only molecular oxygen and water.