Room-temperature coupling of methane with singlet oxygen

Owing to emission of methane (CH4) causing global warming and waste of resources, conversion of CH4 to value-added chemicals can mitigate environmental sustainability and energy concerns. Direct room-temperature coupling of CH4 to form ethane (CH3CH3) challenges chemists owing to the strong C-H bonds requiring high temperature (>700 degrees C) for dehydrogenation of CH4. Oxidative coupling is a promising approach for CH4 conversion to C2H6 using solar energy at room temperature. To achieve high efficiency of C2H6 formation, using an appropriate oxidant is a potential strategy to avoid overoxidation during the CH4 coupling process. Singlet oxygen (O-1(2)) has typically manifested a mild redox capacity with a high selectivity to attack organic substrate CH4. Here, we report a synergistic photocatalytic-oxidative route for direct CH4 coupling. Under solar light irradiation, a high CH3CH3 generation rate of 647 mu mol g(-1) h(-1) is achieved at 25 degrees C. Our work demonstrates that the solar-oxidative route can result in new and useful C1-based catalytic behaviors.