Measurement of Gasoline Exhaust Hydrogen Emissions

Hydrogen is a reactive species involved with many combustion and catalysis reactions. Traditionally studies on hydrogen relied on theoretical calculation of engine out emissions. This study used a mass spectrometer to measure hydrogen emissions at engine out and tailpipe for a port fuelled injection (PFI) gasoline vehicle.

Comparison of measured with calculated for engine out hydrogen showed good agreement. However, catalyst ageing affected post catalyst hydrogen levels to an extent that would be difficult to model by calculation. Study shows that for a detailed understanding of the influence of hydrogen on combustion and catalyst performance the preferred approach is measurement rather than calculation.