N-Doped Porous Carbon Derived by Direct Carbonization of Metal–Organic Complexes Crystal Materials for SO2 Adsorption

Abstract

Three metal–organic complexes crystal materials (MOC-1, MOC-2, and MOC-3) have been hydrothermally synthesized. Driven by C–H···O and C–H···Cl hydrogen bonding interactions, MOC-1, MOC-2, and MOC-3 displayed supramolecular metal–organic frameworks with pcu, bnn, dia topology, respectively. Subsequently, N-doped porous carbons (NPCs) were obtained from carbonization of three metal–organic complexes (MOCs) crystal materials. The resulting NPCs were multiwalled graphite type structures, with high Brunauer, Emmett and Teller surface area (3186.5 m2 g–1), pore volume (2.16 cm3 g–1), and nitrogen content (19.6%), and the N atoms of the MOC precursors were mostly retained. Especially, benefiting from the largest surface area, micropore structure, more disordered stacks of carbon layers, and the largest displacement distance of D band and G band, NPCs showed a significant amount of SO2 adsorption capacity, up to 156.72 mg g–1. The SO2 adsorption capacity increased remarkably over 12 times with the addition of O2 and H2O together. Theoretical calculations indicated that N doping into N-doped porous carbons remodels the local electronic density as well as electrostatic surface potential, enhancing the SO2 adsorption. This work demonstrates a clear and significant advance for preparing N-doped porous carbon materials from MOCs for effective SO2 adsorption.