The Suitability of the Three-way Catalyst for Hydrogen Fuelled Engines: A study in carbon emissions reduction and NOx management.

This experimental study investigates the palladium/rhodium based three-way catalyst (TWC) in a hydrogen-gasoline dual-fuel spark ignition (SI) engine under stoichiometric and lean conditions. The work focused on lean-burn engine operating conditions with the aim of reducing nitrogen oxides (NO_x) emissions during the combustion process, where the TWC is not effective, while improving the thermal efficiency of the engine. Under these leanburn engine conditions, the combustion promoting properties of hydrogen allowed for maintained engine combustion stability as determined by the cycle-to-cycle variation (COV_imep) values even up to ultra lean conditions (λ= 2.0). It was found that by reducing the combustion temperature through the application of lean conditions, engine-out NO_x emissions could be reduced or even eliminated, while under these conditions the TWC was effective in reducing engine-out carbon-based gaseous emissions. [ABSTRACT FROM AUTHOR]