General and Predictable Synthesis of Ultrahigh-Surface-Area Porous Carbons with Superior Yield via Preferential Removal of sp2-Hybridized Atoms

A grand challenge in the state-of-the-art porous carbons is the lack of reliable synthesis strategy for achieving ultrahigh surface areas while maintaining a high carbonization yield. Ultrahigh surface area generally depends on trial and error activation with poor understanding of structural information in the starting carbonaceous matter to predict the ultrahigh porosity. Meanwhile, excessive development of porosity (> 3500 m2 g− 1) will undoubtedly give rise to low carbonization yield (< 10%), thus far restricting cost-effective applications. Here, we report a general and predictable protocol via constructing nitrogen-doped sp2-hybridized carbon atoms in the carbonaceous matter, which guides the pore-creating agents (e.g., KOH) to preferentially etch over sp2- rather than sp3-hybridized atoms, thus greatly increasing the activation reaction efficiency to simultaneously accomplish ultrahigh porosity without sacrificing carbonization yield, a critical paradox in producing carbons. A highest surface area (4482 m2 g− 1) with 10 wt.% carbonization yield and 3500 m2 g− 1 with an unparalleled yield of 35% are achieved so far, which enables great potential in adsorptive-related applications as exemplified by their record-high gas adsorption and supercapacitve performances. Our findings reveal important insights on directed synthesis of ultrahigh-surface-area carbons and provide an impetus for their on-demand applications.