Microporous triazine-based ionic hyper-crosslinked polymers for efficient and selective separation of H2S/CH4/N2

Ionic hyper-crosslinked polymers (IHCPs) are a class of unique porous organic polymers (POPs) that not only have high specific surface area and porosity, but also have abundant anionic and cationic sites. These characteristics make IHCPs potential excellent gas adsorbing materials. In this work, a series of microporous triazine-based IHCPs were prepared through Friedel-Crafts alkylation and quaternization reaction for selective separation of H2S/CH4/N-2. The structure and textural properties of these IHCPs were characterized in detail by FTIR, C-13 solid-state NMR, XPS, XRD, TGA, SEM, TEM, H2S-TPD and N-2 adsorption-desorption experiments, respectively. The H2S adsorption capacity of IHCPs was up to 4.85 mmol & BULL;g(-1) at 25 ? and 1.0 bar, in which IHCPs-2 shows an appreciable IAST selectivity for H2S/CH4 and H2S/N-2 (23.0 and 83.8 at 25 ? and 1.0 bar, respectively). Furthermore, the thermodynamics parameters of H2S absorption, including enthalpy change (& UDelta;H), entropy change (& UDelta;S), and Gibbs free energy (& UDelta;G), were also calculated from isothermal adsorption data, and the results showed that the adsorption process of H2S is exothermic and physical adsorption. This work demonstrated that the microporous triazine-based IHCPs can be used as a promising H2S adsorption material for selective separation of H2S/CH4/N-2 mixed gas.

Automated summary

This study prepared a series of microporous triazine-based IHCPs and characterized their structure and textural properties. It was found that these IHCPs have high H2S adsorption capacity and show potential for selective separation of H2S/CH4/N-2 mixed gas.