A hybrid processing method for high performance hydrogen-selective silica membranes

Development of high performance hydrogen- selective inorganic membrane has become an important requisite for the production of hydrogen, an energy carrier that could cater the ongoing energy revolution. This paper describes a novel, hybrid method to process high performance hydrogen perm-selective membranes by the rapid CVD modification of a sol-gel silica layer. The initial N(2) permeance values through a membrane were brought down by four orders of magnitude to 2.74 X 10(-11) mol m(-2)s(-1) Pa(-1) within 5 min of CVD, while maintaining the H(2) permeance values as high as 6.43 x 10(-7) mol m(-2) s(-1) Pa(-1) (H(2)/N(2) = 2300). It is likely that the reduction in the CVD zone thickness achieved by the presence of pre-existing sol-get silica layer is the reason for the rapid modification of the pore structure to high performance membranes. (c) 2007 Elsevier B.V. All rights reserved.