Triazine-based hyper-cross-linked polymers derived porous carbons for CO 2 capture

Abstract 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  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  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.