Nanoporous molecular basket sorbent for NO2 and SO2 capture based on a polyethylene glycol-loaded mesoporous molecular sieve

Abstract

A novel type of nanoporous molecular basket sorbent (MBS) has been designed for NO₂ and SO₂ capture and separation from gas streams at room temperature based on polyethylene glycol (PEG)-loaded mesoporous molecular sieve SBA-15. The MBS material prepared, PEG(50)/SBA-15, is a nanoporous composite of 50 wt% PEG and SBA-15. The sorption capacity and selectivity of PEG(50)/SBA-15 have been evaluated for NO₂ and SO₂ removal from the simulated gas streams in a fixed-bed flow sorption system at room temperature under atmospheric pressure. It was found that the PEG(50)/SBA-15 sorbent is capable of efficiently removing >99.6% of NO₂ and SO₂ in gas mixtures, i.e., from 2000 to below 5 ppmv NO₂ in N₂ and from 500 to below 2 ppmv SO₂ in N₂, respectively, at ambient conditions with high capacity and selectivity. In addition, the spent sorbent can be regenerated easily and completely by heating to 100 °C. With this new approach, the present study may open a new window for developing high-performance sorbents for SO₂ and NO₂ removal from various gas streams.