Nitrogen-doped microporous carbon materials with uniform pore diameters: Design and applications in CO2 and H2 adsorption

• Published in: Microporous and mesoporous materials 2020-04, Vol.296, p.109992, Article 109992
• Main Authors: Ma, Zhishuang, Yang, Zhenzhen, Zhang, Hongye, Liu, Zhimin
• Format: Article
• Language: English
• Subjects: CO2 adsorption; H2 adsorption; Microporous carbon; Uniform pore diameter
• ISSN: 1387-1811
• DOI: 10.1016/j.micromeso.2019.109992

Nitrogen-doped microporous carbon materials (N-MCs) with uniform pore diameters have promising applications in gas absorption, however their fabrication is challenging. Herein, we report a new approach to prepare N-MCs with uniform pore size using azo-linked organic polymers (AOPs) as the N-containing precursors. The AOPs were synthesized via the reactions of 1,3,5-tris(4-nitrophenyl)benzene (TNPB) and melamine (MA), and their N contents were tuned by changing the molar ratios of MA to TNPB. Followed by calcination of the resultant precursors at 800 °C, porous N-MCs were produced, which were characterized by means of different techniques including FT-IR analysis, N2 sorption, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and elemental analysis. It was demonstrated that the pore diameters of N-MCs could be tuned by changing the MA: TNPB ratio for preparing azo-polymer precursors, and N-MCs with pore size centered at 0.72 and 1.06 nm were obtained. The resultant N-MCs showed excellent CO2 uptake capacity up to 191 mg g−1 at 1 bar and 273 K, with a CO2/N2 selectivity of 58 at 298 K and good H2 adsorption capacity of 14.7 mg g−1 at 77 K. Nitrogen-doped microporous carbon materials (N-MCs) with uniform pore diameters at 0.72 and 1.06 nm were prepared through calcining azo-linked polymers that were synthesized via the reactions of 1,3,5-tris(4-nitrophenyl)benzene and melamine. The resultant N-MCs showed excellent CO2 uptake capacity (up to 194 mg g−1 at 1 bar and 273 K), with a CO2/N2 selectivity of 58 at 298 K and H2 adsorption capacity of 14.7 mg g−1 at 77 K. [Display omitted] •Nitrogen-doped microporous carbon materials (N-MCs) have promising application in CO2 adsorption.•N-MCs with uniform pore size were prepared using Azo-MOPs as the precursors.•N-MCs with uniform pore diameters around 0.78 and 1.06 nm were obtained.•N-MCs showed excellent CO2 uptake capacity up to 194 mg g−1 at 1 bar and 273 K.•N-MCs exhibited good CO2/N2 selectivity of 58 at 298 K and H2 adsorption capacity of 14.7 mg g−1 at 77 K.