Investigation of cyclohexane catalytic degradation driven by N atoms from N₂ discharges

The effect of N₂ discharge products on cyclohexane degradation over a MnO₂/γ-Al₂O₃ catalyst has been evaluated by feeding N₂ discharge products to the catalyst using a specially designed dielectric barrier discharge reactor. At a reaction temperature of 100 ℃, the cyclohexane conversion increased from 2.46% (without N₂ discharge products) to 26.3% (with N₂ discharge products). N- and O-containing by-product (3, 4-dehydroproline) was found on the catalyst surface using gas chromatograph-mass spectrometry identification, in which C=N–C and C=N–H bonds were also confirmed from x-ray photoelectron spectroscopy analysis results. Operando analysis results using diffuse reflectance infrared Fourier transform spectroscopy revealed that N atoms can react with surface H₂O possibly to NH and OH reactive species that have reactivities to promote CO oxidation to CO₂. The mechanism of N-atom-driven cyclohexane degradation to CO and CO₂ is proposed.