A toxic pollutant produced by burning fossil fuels can be captured from the exhaust gas stream and converted into useful industrial chemicals using only water and air thanks to a new advanced material developed by an international team of scientists.

New research led by The University of Manchester, has developed a metal-organic framework (MOF) material that provides a selective, fully reversible and repeatable capability to capture nitrogen dioxide (NO 2 ), a toxic air pollutant produced particularly by diesel and bio-fuel use. The NO 2 can then be easily converted into nitric acid, a multi-billion dollar industry with uses including, agricultural fertilizer for crops; rocket propellant and nylon.

MOFs are tiny three-dimensional structures which are porous and can trap gasses inside, acting like cages. The internal empty spaces in MOFs can be vast for their size, just one gram of material can have a surface area equivalent to a football pitch.

The highly efficient mechanism in this new MOF was characterised by researchers using neutron scattering and synchrotron X-ray diffraction at the US Department of Energy’s Oak Ridge National Laboratory and Berkeley National Laboratory, respectively. The team also used the National Service for Electron Paramagnetic Resonance Spectroscopy at Manchester to study the mechanism of adsorption of NO 2 . The technology could lead to air pollution control and help remedy the negative impact nitrogen dioxide has on the environment.

As reported in Nature Chemistry, the material, named MFM-520, can capture nitrogen dioxide at ambient pressures and temperatures—even at low concentrations and during flow—in the presence of moisture, sulfur dioxide and carbon dioxide. Despite the highly reactive nature of the pollutant, MFM-520 proved capable of being fully regenerated multiple times by degassing or by treatment with water in air—a process that also converts the nitrogen dioxide into nitric acid.