Simultaneous capture of trace benzene and SO₂ in a robust Ni(II)-pyrazolate framework.

Abstract

Benzene and SO₂, coexisting as hazardous air pollutants in some cases, such as in coke oven emissions, have led to detrimental health and environmental effects. Physisorbents offer promise in capturing benzene and SO₂, while their performance compromises at low concentration. Particularly, the simultaneous capture of trace benzene and SO₂ under humid conditions is attractive but challenging. Here, we address this issue by constructing a robust pyrazolate metal-organic framework (MOF) sorbent featuring rich accessible Ni(II) sites with low affinity to water and good stability. This material achieves a high benzene uptake of 5.08 mmol g^-1 at 10 Pa, surpassing previous benchmarks. More importantly, it exhibits an adsorption capacity of ~0.51 mmol g^-1 for 10 ppm benzene and ~1.21 mmol g^-1 for 250 ppm SO₂ under 30% relative humidity. This work demonstrates that a pioneering MOF enables simultaneous capture of trace benzene and SO₂, highlighting the potential of physisorbents for industrial effluent remediation, even in the presence of moisture.