About surface reaction kinetics on probabilistic and fractal substrates

Two models of bimolecular surface reactions [GRAPHICS] occurring on irregular substrates (probabilistic supports and Sierpinski ca rpets) are investigated by means of Monte Carlo Simulations. Steady-state r egimes controlled by the reaction exhibit fractal kinetics features which a re compared to those observed when these reactions are simulated on a regul ar lattice. Noninteger rate orders and modifications of the phase diagram ( case n=2) are presented as a function of the concentration of the inactive sites of the surface. These fractal kinetics properties are tentatively int erpreted in terms of structural specifics that characterize the ramificatio n of both the substrate and the reactive adsorbate. (C) 1999 American Insti tute of Physics. [S0021-9606(99)70233-3].