Vaporizing NOx (NO and NO2) with hot metal?
Thin wall channels (this would be the "steel" plates perhaps) in the device are coated with a wash coat of aluminum oxide which is porous and increases the surface area. This allows more reactions to take place since the converters also contain precious metals such as platinum, rhodium, and palladium e.g. converting NOX into nitrogen and oxygen, hydrocarbons into water and carbon dioxide, and so on. 

These catalytic converters use oxidation and reduction reactions to convert the "toxic" fumes—I'm not certain they are stating to work any differently with this regard than other catalytic converters do though. Oxidation is the loss of electrons and reduction is the gaining of electrons at the molecular level. This in addition to the precious metals help promote the transfer of electrons into the conversion of "toxic" fumes to "non-toxic" fumes.

Furthermore, these can also contain oxygen sensors on them measuring and reporting back to the Engine Control Module the oxygen levels in the exhaust. This will help tell other sensors to adjust air-to-fuel ratio helping to keep the catalytic converter running at optimum efficiency.  

I would say if this device has a patent and has held up to the tests thereof, then it's likely legitimate and accurately effective as advertised by the manufacturer.