In this contribution, mathematical model for the description of solvent evaporation and noble metal precursors crystallization in a porous medium on nano-scale is presented. The methodology is based on the volume-of-fluid method and the model is validated by comparing the numerical simulation results with analytical solutions for evaporation from a single pore and for particle growth and Ostwald ripening of two freely suspended particles in a saturated solution. Impact of process conditions (initial concentration of the metal precursors, temperature, transport properties, nucleation) on the resulting porous catalyst is studied.