Abstract: A comparative assessment of the chromatographic parameters of an Rt-Q-BOND commercial column and capillary columns 30 m × 0.32 mm with layers of functionalized poly(1-trimethylsilyl-1-propyne) (PTMSP/N2O) 0.5 and 0.8 μm thick is made with respect to the products (light (C1–C2) and aromatic hydrocarbons) of the catalytic reaction of ethylbenzene pyrolysis. It is shown that the peak resolution grows along with the thickness of the PTMSP/N2O layer grows. It is found that the measured retention parameters, resolution, and asymmetry of peaks of components on the column with the polymer layer 0.8 μm thick did not change after two years (~15 000 h) of column operation. This testifies to the stability of the PTMSP/N2O stationary phase. It is concluded that columns of the two investigated types selectively separate the products of the ethylbenzene pyrolysis. On the column with the functionalized polymer, the components elute at shorter retention times, and the shapes of the peaks are nearly Gaussian.