General 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. Generally, the realization of the ultrahigh surface area depends on the inherent properties of the starting precursors. 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 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 Brunauer-Emmett-Teller surface area (i.e., 4376 m² g⁻¹) with 10 wt% carbonization yield and 3829 m² g⁻¹ with an unparalleled yield of 35.1 wt% 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.