Impact of activation conditions on the Cu-speciation in Cu-zeolites and its role in the direct methane to methanol conversion.

Cu-exchanged zeolites have proven to be good candidates for direct conversion of methane to methanol (DMTM), with Cu-mordenite (Cu-MOR) zeolite being exceptionally well suited for this task. Recent studies suggest the oxygen in the synthesized methanol to originate from the water rather than the O2 of the initial activation step. Furthermore, preliminary results from our group focusing on the activation of C-H bonds in lower alkanes (≥ C2) over Cu-MOR, find no apparent differences with respect to the activation atmosphere (O2 or He). Therefore, with in situ XAS experiments, we want to monitor the Cu-species and track small variations in the local environment of Cu formed during the activation in different atmospheres (O2, He, H2O). This study promises to shed more insight on and facilitate a better understanding of the nuclearity of the active sites in relation to the methanol productivity, a crucial step for the further improvement of the DMTM reaction.