During the hydrogenative ring-opening reaction of propylcyclobutane over Rh/SiO2 bifurcation was observed. On varying the hydrogen concentration in the reactor a catalytic surface with two steady states was formed. This bistability was found over the "working" catalyst and was attributed to the interplay of adsorbed hydrogen, adsorbed propylcyclobutane, the carbonaceous deposits and the surface or close to surface Rh atoms.