A method for separation of molecular hydrogen from a gaseous mixture containing the molecular hydrogen, which method employs a dense mixed oxide ion/electronic/hydrogen atom conducting membrane or separator having a feed side and a permeate side that enables two mechanisms for hydrogen separation—ambi-polar conduction and hydrogen atom conduction. In this method, at least a portion of the molecular hydrogen is converted on the feed side of the membrane to hydrogen atoms, which hydrogen atoms are conducted through the membrane to the permeate side thereof where they are converted back to molecular hydrogen. The permeate side of the membrane is contacted with steam, forming water and/or steam on the feed side of the membrane and additional molecular hydrogen on the permeate side of the separator.