Design of sustainable V-based hydrogen separation membranes based on grain boundary segregation

作者：Ko Won Seok; Oh Ju Young; Shim Jae Hyeok; Suh Jin Yoo; Yoon Woo Young; Lee Byeong Joo^*

来源：International Journal of Hydrogen Energy, 2014, 39(23): 12031-12044.

DOI：10.1016/j.ijhydene.2014.06.023

• Hydrogen separation membranes
• Inter-diffusion
• Grain boundary segregation
• Atomistic simulations
• Vanadium alloy

Inter-diffusion between vanadium and palladium coating layers in vanadium-based hydrogen separation membranes is investigated by using a computational approach based on first-principles calculations and semi-empirical atomistic simulations, paying attention to the surface stability and the prevention of the degradation of hydrogen permeability. It is found that the governing mechanism of the inter-diffusion is the grain boundary diffusion, and therefore a diffusion barrier based on the grain boundary segregation of impurities can be an efficient way to inhibit the inter-diffusion that causes the degradation. An interesting aspect in previous experimental works that showed a good resistance to the inter-diffusion by an addition of a trace amount of yttrium is discussed from the view point of the grain boundary segregation. An experiment that proves the validity of the present alloy design scheme (inhibition of inter-diffusion using grain boundary segregation) is carried out, and a process to maximize the sustainability of the membrane is also proposed.

• 出版日期2014-8-4