Lower Temperature, Hydrothermally Stable Methane Oxidation Catalysts that Are Sulfur Tolerant

Lean-burn natural gas (NG) engines are a preferred choice for the hard-to-electrify sectors for higher efficiency and lower NOx emissions, but methane slip can be a challenge. New greenhouse gas regulations are pushing these industries to also address methane emissions due to its high global warming potential. Addressing methane emissions using an aftertreatment control solution provides a minimally invasive approach for new engines and offers easy retrofitting to those already in-use in the field. Current Pd-only methane oxidation catalyst (MOC) formulations require high-temperature operation and are prone to deactivation by the high water concentration and presence of sulfur in the exhaust. For an aftertreatment solution to be effective, new MOC formulations need to be active at lower exhaust temperatures below 500°C, be more hydrothermally stable with increased sulfur tolerance. Using modifiers and specific calcination steps, this new alumina-based MOC formulation shows superior activity to the standard Pd/Al2O3 MOC with a comparable Pd loading and under relevant, lean-burn engine exhaust (including NO, CO and H2O) at around 450°C before and after hydrothermal aging (HTA). It has also been shown to be significantly more sulfur tolerant providing a longer useful life of the MOC.

Contact

To learn more about this technology, email partnerships@ornl.gov or call 865-574-1051.