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The O-containing hyper-cross-linked polymers were synthesized from phenol (2-naphthol) and formaldehyde dimethyl acetal by a simple one-step Friedel-Crafts reaction, they were subsequently carbonized using KOH as the activating agent, and their adsorption to CO 2 was carefully tested. The results indicated that these samples had a high Brunauer-Emmett-Teller surface area (up to 2241 m 2 /g), pore volume (up to 1.20 cm 3 /g), CO 2 uptake (up to 6.3 mmol/g at 273 K and 1.0 bar), and CO 2 /N 2 selectivity (up to 96 for the HCPs, and 22.5 for the porous carbon). In particular, the CO 2 adsorption was highly dependent on the ultramicropore volume (pore width<0.7 nm), while the CO 2 /N 2 selectivity mainly relied on the oxygen content and the ultramicropore structure. [ABSTRACT FROM AUTHOR]

The N-containing hyper-cross-linked polymers with different porosity and polarity were prepared from 4-vinylbenzyl chloride and 4-vinyl pyridine by the suspension polymerization and Friedel-Crafts reaction. A carbonization process by KOH chemical activation was carried out for the N-containing hyper-cross-linked polymers, and hence a series of N-doped porous carbons (NDPC) was easily fabricated. These porous materials were comparatively evaluated for CO 2 adsorption. The NDPC were much more efficient than the N-containing hyper-cross-linked polymers for the CO 2 capture and the CO 2 uptake had a linear correlation to the ultramicropore volume (d ≤ 0.8 nm) with R 2  = 0.9737. NDPC-10% possessed the highest CO 2 uptake around 270 mg/g, and had the sufficient CO 2 /N 2 selectivity of 20.2 at 273 K and 1.0 bar. The CO 2 /N 2 selectivity of the N-containing hyper-cross-linked polymers was much higher than the NDPC due to the higher nitrogen content. The isosteric heat of adsorption on the N-containing hyper-cross-linked polymers ranged 29.0–41.2 kJ/mol while that on the NDPC was much lower (24.6–29.2 kJ/mol). The NDPC developed in this study may provide promising candidates for the CO 2 capture. [ABSTRACT FROM AUTHOR]

N-doped porous carbons (NPCs) are promising adsorbents for carbon capture and sequestration. Herein we prepare a series of NPCs derived from triazine-based hyper-cross-linked polymers and tune the porosity and nitrogen content by carbonization temperature and activator. The NPCs prepared at 800 °C using KOH as the activator has the highest Brunauer-Emmett-Teller surface area (3542 m 2 /g) while the NPCs prepared at 700 °C using ZnCl 2 as the activator possesses the highest N content (7.27 wt%). The CO 2 adsorption indicates that the NPCs prepared at 700 °C with KOH holds the highest CO 2 uptake (240 mg/g) while the NPCs prepared at 700 °C with ZnCl 2 owns the highest CO 2 /N 2 selectivity (42.6). The CO 2 uptake at 1.0 bar depends linearly on the cumulative supermicropore volume (d < 1.2 nm) ( V super ), while nitrogen content plays an important role for CO 2 uptake at a low pressure (0.1 bar). CO 2 /N 2 selectivity is mainly related to V super versus the cumulative micropore volume (d < 2 nm) ( V micro ) and nitrogen content, especially pyridinic N and quaternary N. These porous carbons exhibit moderate isosteric heat of adsorption (19.3–28.3 kJ/mol), can be completely regenerated, and show excellent recycling performance. Our study provides promising porous carbons for CO 2 capture and affords effective guideline for designing porous materials with an improved CO 2 capture. [ABSTRACT FROM AUTHOR]