Methane Oxidation to Methanol Catalyzed by Cu-Oxo Clusters Stabilized in NU-1000 Metal–Organic Framework

• Published in: Journal of the American Chemical Society Vol. 139; no. 30; pp. 10294 - 10301
• Main Authors: Ikuno, Takaaki, Zheng, Jian, Vjunov, Aleksei, Sanchez-Sanchez, Maricruz, Ortuño, Manuel A, Pahls, Dale R, Fulton, John L, Camaioni, Donald M, Li, Zhanyong, Ray, Debmalya, Mehdi, B. Layla, Browning, Nigel D, Farha, Omar K, Hupp, Joseph T, Cramer, Christopher J, Gagliardi, Laura, Lercher, Johannes A
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 02.08.2017; American Chemical Society (ACS)
• Subjects: carbon; carbon dioxide; catalysts; coordination polymers; cupric oxide; density functional theory; methane; methanol; oxidation; X-ray absorption spectroscopy
• ISSN: 0002-7863; 1520-5126; 1520-5126
• DOI: 10.1021/jacs.7b02936

Copper oxide clusters synthesized via atomic layer deposition on the nodes of the metal–organic framework (MOF) NU-1000 are active for oxidation of methane to methanol under mild reaction conditions. Analysis of chemical reactivity, in situ X-ray absorption spectroscopy, and density functional theory calculations are used to determine structure/activity relations in the Cu-NU-1000 catalytic system. The Cu-loaded MOF contained Cu-oxo clusters of a few Cu atoms. The Cu was present under ambient conditions as a mixture of ∼15% Cu+ and ∼85% Cu2+. The oxidation of methane on Cu-NU-1000 was accompanied by the reduction of 9% of the Cu in the catalyst from Cu2+ to Cu+. The products, methanol, dimethyl ether, and CO2, were desorbed with the passage of 10% water/He at 135 °C, giving a carbon selectivity for methane to methanol of 45–60%. Cu oxo clusters stabilized in NU-1000 provide an active, first generation MOF-based, selective methane oxidation catalyst.