Investigation of the low-temperature oxidation of n-butanal in a jet-stirred reactor

Abstract

Abstract n-Butanal is a key intermediate formed during the low-temperature oxidation of hydrocarbons and is also a toxic pollutant during the high-temperature oxidation of biofuels. In this work, its low-temperature oxidation chemistry was studied over the temperature range of 500–900 K in a jet-stirred reactor (JSR) at 700 Torr. Synchrotron vacuum ultraviolet photoionization mass spectrometry was employed to identify and quantify the intermediates. A total of 40 species were detected including some reactive peroxy radicals and hydroperoxide species. Speciation measurements obtained in this work can serve as validation targets for new reaction mechanisms, providing new kinetic insights into the n-butanal low-temperature oxidation. Particularly, the O2-addition to the carbonyl radical of n-butanal (n-C3H7CO) proves to be a competing channel with the direct decomposition, which is supported by our experimental results.