Transport of H 2, O 2 and H 2O through single-phase, two-phase and multi-phase mixed proton, oxygen ion, and electron hole conductors

Abstract

This manuscript examines the transport of H 2O, H 2 and O 2 through membranes, which conduct protons (H +), oxygen ions (O −2) and holes ( h ⋅). Transport equations are derived under the assumption of steady state and fast surface kinetics. The specific cases considered here include the transport of H 2O and O 2 through membranes in H 2O–O 2 gaseous mixtures, and the transport of H 2O and H 2 in H 2O–H 2 gaseous mixtures. The transport equations show that Onsager cross coefficients are symmetric, as required. Permeation of H 2O, H 2, and O 2 through single phase, two-phase and multiphase composite membranes is discussed. The analysis shows that the transport of neutral species, namely H 2, O 2, and H 2O, can occur up their chemical potential gradients through the existence of cross terms.