Hierarchical N-Doped Carbons Endowed with Structural Base Sites toward Highly Selective Adsorption and Catalytic Oxidation of H2S

H 2 S catalytic elimination via selective oxidation process has received considerable attention because it can transform highly toxic H 2 S into elemental sulfur under mild condition without thermodynamic limitation. For this purpose, catalysts with high performance in H 2 S capture and selective oxidation are urgently needed. Herein, we report novel nitrogen-doped carbon-based catalysts (denoted as PPy-KOH- T ), which are synthesized by direct carbonization of polypyrrole at 600–800 °C using KOH as an activator. The obtained PPy-KOH- T shows large specific surface areas (1116–3157 m 2 /g), hierarchical structure, and abundant nitrogen active sites. As a result, PPy-KOH- T exhibits high performance in H 2 S selective capture. The H 2 S adsorption capacity of PPy-KOH-700 is as high as 19.7 mmol/g (0 °C, 1 bar), and the ideal adsorption solution theory (IAST) selectivity of H 2 S/N 2 is up to 117.6, which is much better than that of activated carbon (4.8). It is found that PPy-KOH- T could completely catalyze the oxidation of H 2 S into elemental sulfur at temperatures as low as 150 °C. It can be applied to the purification of high-sulfur natural gas and blast furnace gas and the recovery of elemental sulfur. Significantly, the as-prepared catalyst displays superior long-term stability in the desulfurization reaction compared with g-C 3 N 4 and commercial Fe 2 O 3 .