Polyacrylonitrile‐Derived Sponge‐Like Micro/Macroporous Carbon for Selective CO₂ Separation

Abstract

CO capture under a dynamical flow situation requires adsorbents possessing balanced proportion of macropores as diffusion path and micropores as adsorption reservoir. However, the construction of interconnected micro-/macropores structure coupled with abundant nitrogen species into one carbon skeleton remains a challenge. Here, we report a new approach to prepare sponge-like carbon with a well-developed micro-/macroporous structure and enriched nitrogen species through aqueous phase polymerization of acrylonitrile in the presence of graphene oxide. The tension stress caused by the uniform thermal shrinkage of polyacrylonitrile during the pyrolysis together with the favorable flexibility of graphene oxide sheets are responsible for the formation of the sponge-like morphology. The synergistic effect of micro-/macroporous framework and rich CO -philic site enables such carbon to decrease resistance to mass transfer and show high CO dynamic selectivity over N (454) and CH (11), as well as good CO capacity at 298 K under low CO partial pressure (0.17 bar, a typical CO partial pressure in flue gas). The above attributes make this porous carbon a promising candidate for CO capture from flue gas, methane sources and other relevant applications.

Recent Advances in Carbon-Based Adsorbents for Adsorptive Separation of Light Hydrocarbons

“…Binder-free synthesis represents a research frontier. For instance, our group developed a series of carbon pellets derived from functional polymer precursors by a one-step sol-gel method [59,124,125]. Although these carbon adsorbents showed a hierarchically porous structure, the connectivity of the mass transport channels can be further improved.…”

Advances in Post‐Combustion CO2Capture by Physical Adsorption: From Materials Innovation to Separation Practice

“…Under static conditions of 1 bar and 298 K, its CO 2 absorption capacity was 2.62 mmol g −1 . Recently, Guo et al [47] . prepared nitrogen‐rich spongy‐like carbon in the presence of graphene oxide (GO).…”

“…In practical gas adsorption and separation processes, gas feeds on the scale of millions of cubic meters per minute needs to be treated; consequently, the adsorbent needs to be sufficiently stable during multiple adsorption/desorption operations. Unfortunately, impurities in realistic gas feeds, particularly SO 2 , NO x , H 2 S, and moisture would damage their micro‐/macroscopic structures [47,270] . Moreover, a high‐pressure environment would lead to an irreversible structural collapse and the mass flow could give rise to a severe pulverization, resulting in a low number of adsorption cycles [278] .…”

Understanding the CO2/CH4/N2 Separation Performance of Nanoporous Amorphous N‐Doped Carbon Combined Hybrid Monte Carlo with Machine Learning

“…Numerous porous materials have been studied as promising sorbents, including metal‐organic frameworks (MOFs), [ 6–8 ] zeolites, [ 9–11 ] covalent organic frameworks (COFs) [ 12,13 ] and amorphous carbon. [ 14,15 ] Among them, the porous amorphous carbon (aC) is an applied adsorbent in industry, due to its low price, high stability, large surface area and free volume. However, the interaction between most gas molecules and pristine carbonaceous materials is normally weak.…”