The cermet consisting of electronic conductor Ni and proton conductor La(2)Ce(2)O(7) (LDC) shows good chemical stability but poor hydrogen permeability. In order to improve the hydrogen permeability, novel Ni-La(2-x)Sm(x)Ce(2)O(7) (x =0, 0.025, 0.05, 0.075, 0.1 and 0.2) cermets were developed for hydrogen separation. The results show that Sm element doping of LDC can affect the rate of hydrogen permeation, with Ni-La(1.95)Sm(0.05)Ce(2)O(7) possessing the highest hydrogen permeation fluxes. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.