Yu Chang-Yeol, Sea Bong-Kuk, Lee Dong-Wook, Park Sang-Jun, Lee Kwan-Young, Lee Kew-Ho
National Research Laboratory for Functional Membranes, Environment and Energy Research Center, Korea Research Institute of Chemical Technology, PO Box 107, Yuseong, Daejeon 305-600, South Korea.
J Colloid Interface Sci. 2008 Mar 15;319(2):470-6. doi: 10.1016/j.jcis.2007.11.056. Epub 2007 Dec 8.
Ni/alumina composite membranes were prepared and investigated for hydrogen separation at high temperature. alpha-Alumina-supported gamma-alumina composite membranes were prepared by soaking-rolling method. In order to improve H2 selectivity and permeance of the gamma-alumina membranes, Ni was deposited by a soaking process. As a result of a single gas permeation test of the Ni/alumina composite membranes, hydrogen permeance and H2/N2 selectivity at permeation temperature of 450 degrees C were 6.29 x 10(-7) mol/m2 s Pa and 5.2 which exceeded theoretical Knudsen selectivity. Contribution of surface diffusion was investigated by temperature dependence of H(2) permeance. The surface diffusion was observed at higher temperature above 250 degrees C. The Ni deposition on surface of the gamma-alumina composite membrane led to hydrogen permeation via Knudsen diffusion combined with surface diffusion, which gave high H2 selectivity exceeding the Knudsen diffusion mechanism.
制备了镍/氧化铝复合膜并对其在高温下的氢分离性能进行了研究。采用浸泡-滚压法制备了α-氧化铝负载的γ-氧化铝复合膜。为了提高γ-氧化铝膜的氢气选择性和渗透率，通过浸泡工艺沉积了镍。对镍/氧化铝复合膜进行单气体渗透测试的结果表明，在450℃的渗透温度下，氢气渗透率和H2/N2选择性分别为6.29×10(-7) mol/m2 s Pa和5.2，超过了理论克努森选择性。通过氢气渗透率的温度依赖性研究了表面扩散的贡献。在高于250℃的较高温度下观察到了表面扩散。γ-氧化铝复合膜表面的镍沉积导致氢气通过克努森扩散与表面扩散相结合的方式渗透，从而产生了超过克努森扩散机制的高氢气选择性。
