Flue-Gas-Derived Sulfur-Doped Carbon with Enhanced Capacitance

Sulfur dioxide, generally coincident in CO2 sources, is a major air pollutant and causes inconvenient poisoning effects of catalysts in state-of-the-art carbon capture and utilization (CCU) technologies. This study demonstrates an efficient strategy of directly capturing and in situ transforming flue gas into nanostructured sulfur-doped carbon by molten salt electrolysis. The hazardous SO2 is fully captured and sulfur is utilized simultaneously. The obtained S-doped carbon has ultrahigh surface-area-normalized capacitance of 71.5 mu F cm(-2), high gravimetric capacitance of 257.3 F g(-1), excellent cycling stability, and good high-rate capability. The process is realized in molten Li2CO3-Na2CO3-K2CO3-Li2SO4 at 475 degrees C armed with a nickel cathode and a SnO2 inert anode. This continuous-operation process integrates carbon reduction, deep desulfurization, promising potential massive preparation of advanced carbon materials from practical waste gas without purification.