PNNL

Abstract

Copper-oxo clusters exchanged in zeolite mordenite are active in the stoichiometric conversion of methane to methanol at low temperatures. Here we show unprecedented methanol yield per Cu of 0.6, with a 90-95 % selectivity, on a MOR solely containing [Cu3(µ-O)3]2+ active clusters. DFT calculations, spectroscopy characterization and kinetic analysis show that increasing the chemical potential of methane enables the utilization of two µ-oxo bridges out of the three available in the tricopper oxo cluster structure. Methanol and methoxy groups are stabilized in parallel, leading to methanol desorption only in presence of water. This research was supported by the U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences (BES), Division of Chemical Sciences, Geosciences and Biosciences (Transdisciplinary Approaches to Realize Novel Catalytic Pathways to Energy Carriers, FWP 47319). In addition, J.Z. and O.Y.G. acknowledge support by the Inorganometallic Catalyst Design Center, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences under Award #DE-SC0012702. I.L. and M.S-S. are thankful to the Deutsche Forschungsgemeinschaft (DFG) and the TUM International Graduate School of Science and Engineering (IGSSE) for financial support. E.K. and E.A.P. acknowledge SurfSARA and NWO (The Netherlands Organisation for Scientific Research) for providing access to supercomputer resources and the European Research Council (ERC) for funding under the European Union's Horizon 2020 research and innovation programme (Grant Agreement No. 725686). We acknowledge the APS (Sector 20, supported by the U.S. Department of Energy, DE-AC02-06CH11357) and DESY (Hamburg, Germany), a member of the Helmholtz Association HGF, for the provision of experimental facilities for X-ray experiments.