Hierarchical N-doped carbons from designed N-rich polymer: Adsorbents with a record-high capacity for desulfurization

The removal of 4,6-dimethyldibenzothiophene is quite challenging in petroleum refining process. Adsorptive desulfurization is an efficient technique but the capacities and/or poor stability of current adsorbents need to be improved. Here, the fabrication of hierarchical N-doped carbons (NCs) derived from carbonizing the polymerization of 2,4,6-tris(chloromethyl)mesitylene and p-phenylenediamine is reported. The results show that the NCs have developed micropores (0.34–0.93 cm³ g⁻¹) and mesopores (0.15–0.47 cm³ g⁻¹), and their surfaces have abundant pyrrole-like/graphitic N and topological defects and vacancies, and high cycle stability (6 cycles). The typical adsorbent NC-700 shows a record-high capacity of 2.91 mmol g⁻¹ under ambient conditions. The computational results show that the doped N is capable of promoting adsorptive strength by 0.055–0.178 eV. In conclusion, the obtained materials exhibit excellent performance for deep desulfurization, and this work may open up new avenues for the development of efficient adsorbents.