Nitrogen dioxide is a prominent air pollutant produced by internal combustion engines burning fossil fuels as well as by a variety of industrial processes.  It is a toxic material associated with a number of respiratory illnesses. 

Researchers at

the University of Manchester in the UK along with an international team of

scientists have developed a new advanced material that can convert nitrogen

dioxide from an exhaust gas stream into useful industrial chemical using only

water and air.

The material is a metal-organic framework (or MOF) that provides a selective, fully reversible, and repeatable capability to capture nitrogen dioxide.  MOFs are tiny three-dimensional structures that are porous and can trap gases inside as though there were tiny cages.  MOFs have enormous amounts of surface area for their size.  One gram of material can have a surface area as large as a football field.

The material,

named MOF-520, can capture nitrogen dioxide at ambient temperatures and

pressures and even at low concentration and during flow in the presence of

moisture, sulfur dioxide, and carbon dioxide. 

Such conditions are typical of the exhaust of internal combustion

engines. In fact, the process works best at the typical temperature of

automobile exhausts.

Once the

nitrogen oxide is absorbed, treating the material with water in air converts it

into nitric acid and restores the MOF for additional use.  Nitric acid is the basis of a multi-billion

dollar industry with uses including agricultural fertilizers, rocket

propellant, and nylon.  Thus, there is

great potential for recouping the costs of using the MOF technology and even

profiting from it.

It would be

great to convert a toxic pollutant into valuable industrial chemicals.

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Clean air research converts toxic air pollutant into industrial chemical

Photo courtesy of the University of Manchester.

Earth Wise is a production of WAMC Northeast Public Radio.