Abstract: A new type of silica-modified membrane has been developed by the high-temperature, atmospheric-pressure CVD of Vycor glass. The new membrane, Nanosil, showed unprecedented selectivity to hydrogen (100%), without loss of permeability compared to the porous Vycor precursor. The membrane also showed high stability under hydrothermal conditions over prolonged time. The suitability of a Rh/Al2O3 catalyst for the methane reforming with carbon dioxide was also demonstrated. The limitations imposed by thermodynamics on methane conversion have been circumvented by the use of membranes to preferentially remove hydrogen during reaction. The shortcoming of the Knudsen mode of diffusion was overcome by the development of the modified porous glass membrane.