Direct oxidation of methane to methanol over copper and zinc synergistic co-modified H-ZSM-5 catalyst

• The methanol yield of 44,302.70 μmol·g cat −1 ·h −1 was obtained over 1Cu/2Zn-ZSM-5. • Zn species modulates the electronic state and coordination structure of Cu species. • Zn increased the proportion of active Cu species bound to extra-framework oxygen. • The bis (μ-oxo) dicopper was identified as the active site for methane oxidation . Great expectations have been placed on bimetallic co-modified zeolite for the direct oxidation of methane to methanol. In this work, H-ZSM-5 zeolite was modified with bimetallic copper and zinc via ion-exchange method. Numerous experiments were conducted and the methanol yield of 44,302.70 μmol·g cat −1 ·h −1 was obtained over 1Cu/2Zn-ZSM-5 catalyst. A series of characterization analyses confirmed that the introduction of Zn increased the proportion of active Cu species bound to extra-framework oxygen by altering the electronic state of copper. The bis (μ-oxo) dicopper ligand was identified as the active site for methane oxidation. The possible reasonable reaction pathway was the free radical reaction. This work provides a valuable guidance for the preparation of co-modified zeolite catalysts for the direct oxidation of methane to methanol.