For solving this stiff system of ordinary differential equations, the numerical Adams/BDF method with automatic stiffness detection and switching was used . in a range from 10 -4 to 10 -1 cm -3 . For each reaction conditions, the 7 points of 𝑉 were uniformly spaced in a logarithmic scale across the chosen range. In the case of training the baseline model (see the baseline model), the data with zero molar flows of CO2 + CO or zero flow of H2 were additionally added. In these cases, the molar flows are constant along the reactor length and equal to the molar flows at the reactor inlet. To make the modelling task more realistic, we added Gauss noise to the data to imitate an experimental error. Four training sets with 0.0, 2.5%, 5.0%, and 10% noise were generated.