Steady state multiplicity and partial internal wetting of catalyst particles

The partial internal wetting of spherical catalyst particles exposed to saturated vapor is investigated here by considering the interplay of capillary condensation phenomena and thermal effects for a first‐order irreversible reaction. It is shown that for certain very narrow ranges of parameters steady states can exist in which the macropores are vapor‐filled while micropores in an inner core, or an outer shell, are liquid‐filled. Under certain conditions even two such steady states are found, although only one of them can be stable. In addition to these there exist states in which all the micropores are liquid‐filled or those in which the entire particle is internally dry.