Water Is the Oxygen Source for Methanol Produced in Partial Oxidation of Methane in a Flow Reactor over Cu-SSZ-13

Direct oxidation of methane to methanol is a long-standing challenge in the heterogeneous catalysis community. This Communication demonstrates that water, not dioxygen, is the main source of the oxygen present in the methanol produced in the partial oxidation of methane to methanol over Cu-SSZ-13 in a continuous-flow reactor. This is confirmed by experiments performed in the absence of molecular oxygen and with the use of ¹⁸O-labeled water. These findings should lead to new approaches for improving the partial oxidation properties of copper zeolites.