gamma-MnO2 nano-sieve membrane was synthesized using gamma-MnO2 nanometer powders by suspending particles sintering method. The results of BET, AFM, and SEM indicate that gamma-MnO2 nano-sieve membrane with a thickness of about 2 mum is porous (pore size 4 nm), and has a smooth surface. The results of XRD and TPR exhibit that the phase transformation which can be suppressed at La/Mn = 0.15, and the activity of oxygen center of gamma-MnO2 nano-sieve membrane (La/Mn = 0.15) is slightly lower than that of gamma-MnO2 nanometer powders. gamma-MnO2 nano-sieve membrane shows a higher separation factor of H-2/Ar in the range of 50-300 degreesC. In addition, the gamma-MnO2 nano-sieve membrane was applied to the membrane reactor for cyclohexane oxidative dehydrogenation, and the effect of temperature on cyclohexane conversion was investigated. The result shows that cyclohexane conversion in the gamma-MnO2 nano-sieve membrane reactor is higher than that in the conventional packed bed reactor. (C) 2004 Elsevier B.V. All rights reserved.