Abstract
In order to elucidate the urea decomposition process for constructing the SCR catalyst model, an accurate quantitative measurement method for isocyanic acid, which is an intermediate product of urea, is required. In this study, the development of standard gas generation method of isocyanic acid and the measurement of isocyanic acid with Fourier Transform Infrared Spectrometer（FT-IR）in synthetic exhaust gases consisting of CO, CO2, NO, NO2, NH3, N2O, and H2O, were carried out. As a result, it is possible to measure the HNCO concentration up to 150 ppm by FT-IR. The measurement accuracy (defined as twice the standard deviation) was obtained to be ± 2.0 to 2.9 ppm.
