Fig. 4: Tandem photo-oxidation of CH4 to CH3OH at the reticular gas-solid interface.

a Comparison of the CH3OH yields (left axis) and selectivity (right axis) on Pd1FeOx/aUiO(H) membrane nanoreactor (gas-solid system) and particles (liquid-solid system) under different flow rates of feed gas. Reaction conditions: 50 mg of MOF catalyst, 1 hour, 25 oC, feed gas with 50% CH4/50% O2, 1200 revolutions per minute (liquid-solid system), and under simulated sunlight irradiation (AM 1.5 G). b Time-on-line water uptake (right axis) and amounts of residual CH3OH and H2O2 (left axis) within the MOF membrane. Reaction condition: 150 sccm humidified feed gas, 25 oC, 1 hour. c Water uptake (right axis) and amounts of residual CH3OH and H2O2 (left axis) within the MOF membrane under different system temperatures. Reaction condition: 150 sccm humidified feed gas, 1 hour. d Comparison of the CH3OH productivity (left axis) and selectivity (right axis) on Pd1FeOx/aUiO(H) membrane (gas-solid system) and particles (liquid-solid system) under different temperatures. e Long-term performance test of the GDL-equipped Pd1FeOx/aUiO(H) membrane under the optimized reaction condition. f Photo-oxidation of CH4 to CH3OH by air and tap water under natural solar light. The error bars and bands correspond to the standard deviation of three independent measurements.