Boosting SO₂ Capture within Nitrogen-Doped Microporous Biocarbon Nanosheets

Abstract

The capture of corrosive SO2 is of great importance in power plants but remains an energetically challenging process. We herein report a strategy to boost SO2 capture under low partial pressure conditions using cost-effective bio-resourced porous carbons (PCs), which involves controlling the microporosity and nitrogen content of nanosheet-like biocarbons to enhance interactions with SO2. This approach uses inexpensive biomass-derived humic acid as a precursor and melamine as a nitrogen source, where the N-doping level, porosity, and morphology are effectively regulated by Pluronic P123-induced self-assembly. The obtained PCs revealed a new record-high adsorption capacity (7.9 mmol/g at 25 °C/0.25 bar) for SO2 with an acceptable recyclability (over three cycles), which exceeded state-of-the-art porous sorbents. The strong affinity toward SO2, which was exemplified by in situ spectroscopic investigations and quantum-chemical calculations, was mainly attributed to strong hydrogen bonding of SO2 with −CH2 or −CH groups adjacent to the nitrogen atoms in the backbone as opposed to SO2-nitrogen interactions. This method opens a novel route to the preparation of biocarbon materials exhibiting specific morphologies and high porosities, in addition to contributing to the development of a potential method for the capture of SO2 by tailorable PCs in industrial processes.

Synthesis of triphenylamine-based nanoporous organic polymers for highly efficient capture of SO2 and CO2

“…Compared to conventional absorption processes, physisorption is known to be a powerful strategy for the convenient and energy-efficient capture of SO 2 , and involves the use of various porous adsorbents, such as porous carbon, [6][7][8][9][10][11] metal-organic frameworks (MOFs), [12][13][14][15][16][17][18][19][20][21] and nanoporous organic polymers (NOPs), [22][23][24][25][26][27] which serve as major adsorbents for physisorption. Among these materials, NOPs have been regarded as promising candidates for SO 2 capture due to their wide range of reactions, high surface area, and excellent chemical and thermal stabilities.…”

Tuning the Adsorption Capacities of Nanoporous Polyaminal Networks through Substituent Groups

“…Nanoporous organic polymers (NOPs) have emerged as promising adsorbents for NH 3 , SO 2 , and iodine vapor (I 2 ), and some researchers have reported that the adsorption performance of NOPs surpasses that of porous carbon and metal–organic frameworks. − The stability and easy functionalization of NOPs have contributed to the growing significance of the polymers. Researchers have synthesized various NOPs to address concerns related to toxic gases and radioactive pollutants.…”