In this work, a study regarding removal of O-2 from post-combustion flue gas using polymer membrane for CO2 capture has been performed. A facilitated transport hollow fiber membrane was prepared and the morphology was examined by scanning electron microscope to understand the correlation of the morphology with the permeation of the membrane. Chemical characterizations of the membranes were conducted by Attenuated total reflectance Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy analysis. The effects of the parameters involved in the spinning procedure of polyethersulfone hollow fiber, poly(n-butyl methacrylate) layer deposition, and cobalt tetraphenylporphyrin complex selective composite membranes were investigated. As a result, the maximum ideal gas selectivities for O-2/N-2 and O-2/CO2 were achieved at 3.2 and 1.17, respectively, at a pressure of 0.098 bar, with a considerably high O-2 permeance of 17 GPIJ for a M4 membrane. This membrane showed facilitated oxygen transport with nitrogen and carbon dioxide at low pressure. The convinced changes in the polymer morphology and separation performance data were evaluated to single gas permeation. Obtained results are useful to develop this membrane further for oxygen removal from flue gas in the area of CO2 capture and storage as a pretreatment process for prevention of the degradation of CO2 absorbents. (C) 2016 Elsevier Ltd. All rights reserved.