Experimental study of nitropropane pyrolysis with molecular-beam mass spectrometry and tunable synchrotron VUV photoionization. Part II. The flow reactor pyrolysis of 2-nitropropane

Abstract

An experimental study of 2-nitropropane (2-NP) pyrolysis was performed in a flow reactor at low pressure (4.0 kPa) and in the temperature range of 523–923 K. The pyrolysis species were detected with the tunable synchrotron vacuum ultraviolet (VUV) photoionization and molecular-beam mass spectrometry (MBMS) techniques. Species from m/z = 15 to 87, such as radicals of CH3, C2H5, C3H5 and C3H7; isomers of C3H4 (allene and propyne), C5H8 (1,3-pentadiene and cyclopentene), were identified from near-threshold photoionization efficiency (PIE) spectra. Four nitrogenous intermediates never reported in the homogeneous pyrolysis of 2-NP (i.e., 2-propen-1-imine, 2-propen-1-amine, acetamide and 2-nitropropene) were identified in this work. The mole fraction profiles of the pyrolysis species were evaluated at different temperatures. Based on the experimental findings, the pyrolysis pathways of 2-NP were discussed.