Preparation and performance of thin-layered PdAu/ceramic composite membranes

摘要: Preparation of 3-5 mu m thick, hydrogen-selective PdAu layers via sequential electroless plating Pd and Au onto ceramic microfiltration membranes was investigated employing a cyanide-free bath. The deposition rate strongly dependent on bath temperature alkalinity reaching an optimum at 333 K pH 10. Homogenous alloying the separate metal under atmospheric H(2) proved to be protracted process required approximately week 873 for layer as thin 3 gm. After 300 h annealing 823 5 gm thick composite membrane still exhibited gradient declining from 7.4 at.% top surface 5.5 support interface despite that permeation had become stable. Nonetheless, very high permeability e.g. 1.3 x 10(-8) mol m(-2) s(-1) Pa(-0.5) 673 K, but it decreased much faster with below 573 than above, likely due change bulk H diffusion-controlled adsorption or desorption-limited transport. withstood cycling between 523 723 in well showing differing thermal expansion joined metallic materials stayed within tolerance range up K. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.