CO2-enhanced hydrogen permeability of dual-layered A-site deficient Ba0.95Ce0.85Tb0.05Zr0.1O3-δ-based hollow fiber membrane

Abstract

Hydrogen (H2)-selective proton conducting perovskite membrane is the low cost alternative of palladium membrane. In this work, we report the preparation of an A-site deficient Zr-doped proton conductor composition of Ba0.95Ce0.85Tb0.05Zr0.1O3-δ (BCTZ) in the dual-layer hollow fiber configuration consisting of Ni-BCTZ inner porous layer and BCTZ outer dense layer, denoted as BCTZ/Ni-BCTZ hollow fiber via co-spinning, co-sintering, and reduction (in hydrogen) processes. The presence of Zr4+ in BCTZ perovskite lattice leads to higher CO2 resistance for BCTZ relative to Ba0.95Ce0.95Tb0.05O3-δ (BCT) as revealed by their CO2-temperature programmed desorption results. H2 permeation flux of dual-layer BCTZ/Ni-BCTZ hollow fiber reaches a maximum of 0.41mLmin−1cm−2 at 900°C. When CO2 was introduced in the permeate side, H2 permeation flux was enhanced with respect to the CO2-absent case, which is attributed to the presence of reverse water-gas shift reaction that consumes the permeated H2 to produce carbon monoxide and water. The dual-layer BCTZ/Ni-BCTZ hollow fiber showed stable H2 permeation fluxes when operated at 800°C in CO2-containing permeate atmosphere for 25 days. Its original morphology and structure were retained following this long term operational test; highlighting its potential use for H2 separation in CO2-containing reactions and processes.