Modelling reduction of nitric oxide by hydrogen over supported catalysts (Q2038935)

The three stages reduction of nitric oxide by hydrogen over a catalyst has been studied by a mean field model. It is assumed that the endothermic reaction takes place in the diffusion layer at the catalytic surface and corresponding transient molecular diffusion equations for the reactants nitric oxide, NO and hydrogen, H\(_2\) are presented under the assumption of no diffusion across the boundary. A conjugation condition is also provided. A similar set of molecular diffusion equations for the products nitrogen, N\(_2\), water, H\(_2\)O, ammonia, NH\(_3\) and nitrous oxide, N\(_2\)O are written. The simultaneous diffusion equations are numerically solved by alternating direction explicit numerical scheme. It has been numerically shown that the reaction being non-autonomous function of time has two local maxima resulting into the increase of the surface reactivity. As the paper provides important information to the air pollution caused by the motor vehicles, an important parameter, temperature is missing from the formulation.