New research article from Prof. Maricruz Sánchez-Sánchez (E166-03-1) in the Journal of the American Chemical Society, titled “Speciation and Reactivity Control of Cu-Oxo Clusters via Extraframework Al in Mordenite for Methane Oxidation, opens an external URL in a new window”. In collaboration with the groups of Evgeny Pidko (TU Delft) and Johannes Lercher (TU München), they studied the structure of nanoscopic copper oxide clusters, hosted in zeolites, that are able to selectively convert methane into methanol. They obtained a quantitative description of the types of active metal-oxo clusters hosted in the microporous channels of highly active Cu-mordenite (CuMOR) materials. Theoretical assessment of the most stable structures, together with spectroscopic characterization, allowed the description at molecular level of two types of active clusters present in CuMOR materials, namely a monometallic Cu-oxo and a bimetallic Cu-(Al)-oxo cluster formed via reaction of exchanged Cu with extraframework Al.
This work shows how important is, for the activity of metal exchanged zeolite catalysts, the competition between different metal-oxo cationic structures, stoichiometries and locations within the framework. It also sheds light on the importance of reacting defects and extraframework Al species in zeolites. The results here will aid the synthesis of novel zeolite-based catalysts hosting metal-oxo ensembles with exceptional catalytic properties.