High oxygen production membranes by Ag catalytic surface modified BSCC perovskite

Abstract

This work shows the preparation, characterisation and oxygen performance of catalytic surface modified Barium Strontium Cobalt Copper (BSCC) perovskite hollow fibres for oxygen separation from air. BSCC hollow fibres were prepared via a phase inversion and sintering method with an outer diameter of ∼ 1.28 mm and a wall thickness of ∼ 0.47 mm. Subsequently, surface modification was carried out by the deposition of Ag nanoparticles as catalyst, resulting in Ag-BSCC hollow fibres. The effect of the catalyst was significant as oxygen fluxes for the Ag-BSCC hollow fibres were always higher than those of the blank BSCC hollow fibre. The Ag-BSCC hollow fibre reached very high oxygen fluxes of 30.6 mL cm−2 min−1. The maximum oxygen flux increment of 19.4 mL cm−2 min−1 over the blank BSCC hollow fibre is one order of magnitude higher than the majority of catalyst surface modified perovskite hollow fibres to date. In addition, the surface modified Ag-BSCC hollow fibre reduced the apparent energy of activation by 46% as compared to the blank BSCC hollow fibre, thus overcoming the rate limiting step of oxygen surface reaction. A mechanism is provided for the high performance of the Ag-BSCC based on three phase transitions of the BSCC perovskite structure as ascertained by high temperature HT-XRD and the oxygen spillover effect of the Ag nanoparticles.