New mesoporous silicalite-2, ZSM-11, and titanosilicalite-2 zeolite single crystals were synthesized by use of carbon particles as a mesopore template. After removal of the carbon particles by combustion, zeolite single crystals with intracrystalline mesopore volumes between 0.31 and 0.44 cm(3)/g were isolated. All samples were characterized by XRD, SEM and adsorption measurements. Isomerization and cracking of n-hexadecane, and epoxidation of oct-1-ene and styrene were chosen as model test reactions. The mesoporous zeolite single catalysts were generally found to exhibit high activity in these model reactions. The advantage of introducing an intracrystalline mesopore system into zeolite catalysts is attributed to the resulting improvements in the mass transport to and from the active sites. This is particularly important for more bulky reactants, intermediates and products and especially under experimental conditions giving high reaction rates.