In this work, the application of an epoxy resin cured with ammonium ionic liquids as a support for palladium complex catalyst is reported. Supports based on epoxy resin were obtained as a result of the use of ionic liquids: didecyldimethylammonium tetrafluoroborate [d₂m₂am][BF₄], 1-methyltheobromine tetrafluoroborate [mthb][BF₄], didecyldimethylammonium theobrominate [d₂m₂am][thb], didecyldimethylammonium theophyllinate [d₂m₂am][thp] as cross-linking agents. The characterization of polymeric supports and heterogenized palladium catalysts has involved research methods like time-of-flight secondary ion mass spectrometry (TOF-SIMS), infrared spectroscopy (IR), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS). The activity and stability during long-term use of the investigated catalytic systems were tested in a model Heck reaction. The influence of the type of ILs used as epoxy hardeners on the catalytic properties of epoxy-supported palladium catalysts is discussed.