Development of lower temperature Methane Oxidation Catalyst (MOC) for lean natural gas vehicles

Melanie  DeBusk, NTRC-Oak Ridge National Laboratory

There is a new resurgence in natural gas vehicle engines research due to the abundant availability of natural gas in the United States.  Lean-burn natural gas engines offer the potential of increased efficiency compared to current stoichiometric technology. However, lean engine operation also brings with it lower exhaust temperatures which can make emissions control solutions more difficult, especially for conversion of the unburned methane.  While methane is not included in current hydrocarbon regulations, it is a potent contributor to greenhouse gas (GHG) emissions having 34 times greater impact than CO₂. Current state-of-the-art methane oxidation catalyst (MOC) technology requires high exhaust temperatures to convert most of the methane emissions.  The development of a lower temperature MOC which builds on the excellent high temperature MOC activity of Palladium (Pd) by modifying supported Pd with a second metal to promote oxidation at low temperatures will be presented.