A research team led by scientists from The University of Manchester has figured out a new way of making toxic pollutants helpful. The system uses the nitrogen dioxide (NO2) in exhaust gas streams from fossil fuel power plants to produce industrial chemicals like nitric acid with only the input of water and air. This twist on a preexisting technology is detailed in the journal Nature Chemistry.
Similar to past developments, the system uses a metal-organic framework (MOF) material, meaning a material that is made of super small 3D porous structures that are able of capturing gases. In the case of this MOF, NO2 is the main target for capture.
Although MOFs are small, their structures are such that their surface area is huge. According to Science Daily, one gram of material can have a surface area equivalent to a football pitch! That means that they are extremely efficient at capturing gases.
"This is the first MOF to both capture and convert a toxic, gaseous air pollutant into a useful industrial commodity,” said lead author Dr. Sihai Yang, who is a senior lecturer at The University of Manchester's Department of Chemistry.
But what makes this MOF special in comparison to other MOFs? Called the MFM-520, this technology is able to withstand the toxicity of NO2 in order to capture it at ambient pressures and temperatures in the presence of moisture, sulfur dioxide and carbon dioxide. This versatility means that it be used in many different settings.
To figure this out, the researchers used neutron spectroscopy and computational techniques to see how MFM-520 captures nitrogen dioxide molecules. "The characterization of the mechanism responsible for the high, rapid uptake of NO2 will inform future designs of improved materials to capture air pollutants." said first author, Jiangnan Li.
The scientists hope that their development of this technology will lead to improvements in controlling the polluting effects of nitrogen dioxide for the environment, and particularly for air pollution control.