The reactions of dry (CO2) reforming and partial oxidation of methane have been investigated in a membrane reactor. The membrane is composed of a dense thin silica (SiO2) film supported on porous Vycor tubes and was synthesized by chemical vapor deposition. The hydrogen permeance of the membrane was 0.2-0.3 cm(3)/(cm(2) min atm) at 600 degrees C combined with a H-2/N-2 selectivity of 200-300. Significant increases in methane conversion were attained in both reactions at 500-750 degrees C, albeit at very low space velocities. The membrane permeance declined by similar to 50% after exposure to feeds containing H2O, but otherwise exhibited excellent stability under reaction conditions.