Non-catalytic gas phase NO oxidation in the presence of decane

Experiments without a catalyst revealed that NO was oxidized in a diesel exhaust gas phase mixture due to the presence of n-C10H22 (decane). This reaction was observed to occur following the low temperature oxidation catalyst test protocol (LTC-D) defined by U.S. DRIVE. The purpose of LTC-D conditions is to simulate an after treatment diesel combustion gas mixture in order to test candidate catalyst materials. 100% NO conversion was observed, without a catalyst, after beginning to react at 330 degrees C accompanied by consumption of decane. After experiments that isolated hydrocarbons, ethylene was also observed to facilitate NO oxidation to a lesser degree (>470 degrees C). Density functional theory (DFT) calculations were conducted to investigate thermodynamically possible initiating elementary steps during n-C10H22 consumption and NO oxidation. Two feasible intermediate radicals to oxidize NO to NO2 are center dot C10H21O2 and center dot HO2.

Automated summary

Experimental results showed that NO in a diesel exhaust gas mixture can be oxidized without a catalyst due to the presence of decane, with ethylene also facilitating the oxidation process to a lesser degree. Density functional theory (DFT) calculations were conducted to investigate the possible initiating steps during decane consumption and NO oxidation process.