A new class of proton-conducting glass composite membranes based on phosphosilicate (P2O5-SiO2) mixed with phosphomolybdic acid (PMA) and zirconium oxide (ZrO2) composite was investigated. Glass electrolytes consisting of this novel combination were characterized with pore property measurements. Fourier transforms infrared (FTIR) spectroscopy, impedance spectroscopy, hydrogen permeability measurements and electrochemical analysis. Heteropolyacid (HPA)-containing inorganic glass composite membrane that have pores with similar to 3 nm diameters are more appropriate for developing fast proton-conducting glasses. PMA-doped ZrO2-P2O5-SiO2 glass membranes exhibited high proton conductivities and showed high hydrogen permeability. A glass composite membrane (2PMA/4ZrO(2)-4P(2)O(5)-90SiO(2) mol%) was fabricated and demonstrated a power density of 32 MW/cm(2) at 29 degrees C and 30% relative humidity under hydrogen and oxygen feed mode. (C) 2009 Elsevier B.V. All rights reserved.