Hydrogen separation and stability study of ceramic membranes based on the system Nd5LnWO12

This contribution presents the preparation, permeation and stability study of mixed protonic-electronic conducting membranes based on the system Nd₅LnWO₁₂. The tungstates Ln₆WO₁₂ are proton conducting crystalline materials, which show sufficient protonic and electronic mixed conductivity and stability in moist CO₂ environments to consider them as potential candidates for the separation of hydrogen at high temperatures. Hydrogen separation properties of A-substoichiometric Nd₆WO₁₂ and Nd₅LaWO₁₂ were systematically analyzed, i.e. the influence of the H₂ concentration in feed stream, humidification degree and operating temperature on the hydrogen separation was studied. Finally, the stability of these materials at different temperatures and CO₂-rich and sulfur-containing environments was evaluated.