An experimental study on the non-catalytic NO oxidation using methanol, ethanol, or acetaldehyde as an additive was performed, and the results were investigated by numerical analysis and sensitivity analysis using a chemical reaction model. It is found that the maximum NO oxidation efficiency when employing methanol is greater than 0.85, whereas the maximum using ethanol is approximately 0.6. Although it is known that methanol and ethanol have different oxidation reaction routes, non-catalytic NO oxidation may even be realized using the latter. Moreover, relative to utilizing alcohol, lower oxidation efficiency are observed using acetaldehyde. Thus, employing alcohols with ignition points above 600 K may be suitable for the non-catalytic NO oxidation.