A silylated ionic liquid (IL)-derived organosilica membrane was prepared on the outer surface of a porous alumina substrate. Its separation properties for binary methanol/H-2 and H2O/H-2 mixtures, and a methanol/ H2O/H-2/CO2 quaternary mixture were studied in the temperature range from 20 to 200 degrees C. The separation factors for methanol/H-2 in the binary system were 12-71. The membrane also showed high H2O/H-2 separation performances in the quaternary system, and the presence of H2O and CO2 in the feed stream did not affect the methanol permeation performance. The silylated IL-derived organosilica membrane showed an excellent potential for the simultaneous separation of methanol and H2O from methanol synthesis gas.