Identification of hydrogen permeability and thermal desorption parameters of vanadium-based membrane

Abstract

The paper implements a two-stage “penetration + thermal desorption” experiment for the complex estimation of hydrogen permeability and thermal desorption parameters (sorption, dissolution, diffusion and desorption) of vanadium-based membrane. A gradual growth of the thermal desorption flux at high temperature is interpreted as a lowering of the potential surface barrier (primarily due to the loss of oxides). Indirect evidence of that is the stability of the critical temperature. Effectively, this entails a reduction of the desorption activation energy. The obtained effective values of the physicochemical parameters describe a series of experimental curves (at different initial sample temperatures, different molecular hydrogen input pressures, different heating rates at the TDS stage) and allow modeling numerically the penetration and thermal desorption across a wide range of conditions (including experimentally difficult ones) and estimating quantitatively the spectrum's reaction to variation of the limiting factors.