Using the principles of electrochemical kinetics it is possible to describe the rate of formation of precursors able to inject electrons in the conduction band of porous silicon layers submitted to galvanostatic creation of holes in the valence band. In this way it becomes possible to explain the shape of the electroluminescence peaks emitted in porous silicon layers, both in the presence and in the absence of H2O2. The kinetic arguments give account of the experimental dependences found between the intensity of the electroluminescence and the potential at which a maximum intensity is observed on the H2O2 concentration. The theoretical description is demonstrated to be valid, notwithstanding the model accepted for explaining the origin of luminescence in porous silicon.