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

Journal of the American Chemical Society

5 years ago

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

Manuel A. Ortuño, Aleksei Vjunov, Nigel D. Browning, Christopher J. Cramer, Zhanyong Li, Laura Gagliardi, Joseph T. Hupp, Dale R. Pahls, Debmalya Ray, Omar K. Farha, John L. Fulton, Maricruz Sanchez-Sanchez, B. Layla Mehdi, Jian Zheng, Johannes A. Lercher, Takaaki Ikuno, Donald M. Camaioni

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.

Publisher URL: http://dx.doi.org/10.1021/jacs.7b02936

DOI: 10.1021/jacs.7b02936