State of the art developments in oxidation performance and deactivation of diesel oxidation catalyst (DOC)

Abstract

State-of-the-art developments in oxidation activity and deactivation mechanisms of the diesel oxidation catalyst (DOC) are reviewed. The effect of temperature, hydrocarbons, CO, H2O, hydrogen, NO, oxygen, NO2, precious metals, and catalyst zoning on DOC's performance is analyzed. CO, NO, and hydrocarbon oxidation is self-inhibited. Hydrogen reduces the light-off temperatures of CO and hydrocarbons. Oxygen and NO2 act as oxidants. Hydrothermal, sulfur, chemical, and hydrocarbon poisoning are primary deactivation mechanisms. Hydrothermal deactivation is the leading cause of Pt-catalyst, and others are less severe. Further improvements regarding biodiesel impact, phosphorous poisoning, and hydrothermal stability are needed to advance DOC science.

Keywords

• Diesel oxidation catalyst
• DOC
• Diesel engine
• Environmental catalysis
• Deactivation
• PGM