Direct oxidation of methane to oxygenates on supported single Cu atom catalyst

• Stable HZSM-5 supported single Cu atom catalyst has been synthesized for direct oxidation of CH4. • Each isolated Cu atom stabilized by four O moieties on the ZSM-5 possesses uniform Cu1-O4 entity. • Cu1/ZSM-5 SAC shows comparable catalytic performance to that of state-of-the-art noble catalysts. • The unique Cu1-O4 entity preferentially activate CH4 and prevent CH3OH from over-oxidation. Catalytically converting CH 4 to chemicals and fuels is of paramount importance but remains a major challenge to simultaneously obtain high activity and selectivity. Here, we report Cu 1 /ZSM-5 single atom catalyst is highly active (C1 oxygenates productivity of 4800 μmol⋅g cat −1 at 50 °C and 12,000 μmol⋅g cat -1 at 70 °C within 30 min) and selective (C1 oxygenates selectivity of 99 % at 50 °C) for direct CH 4 oxidation, comparable to most of those state-of-the-art noble metal catalysts. The combined DFT calculation, electronic microscope, X-ray absorption and electron paramagnetic resonance results confirm that each isolated Cu atom stabilized by four O moieties on the ZSM-5 support possesses uniform Cu 1 -O 4 entity as active site and preferentially activates CH 4 instead of CH 3 OH that is advantageous for highly selective C1 oxygenates production, especially for methanol. Our molecular-level finding on the atomic structure of Cu active site paves the way to design better catalysts for methane conversion.