Rapid glycine-nitrate combustion synthesis of the CO2-stable dual phase membrane 40Mn1.5Co1.5O4−δ–60Ce0.9Pr0.1O2−δ for CO2 capture via an oxy-fuel process

Abstract A rapid one-pot combustion synthesis method based on glycine–nitrate, has been applied to prepare a novel oxygen transporting dual phase CO 2 -stable membrane of the composition 40 wt% Mn 1.5 Co 1.5 O 4− δ –60 wt% Ce 0.9 Pr 0.1 O 2− δ (40MCO–60CPO). After sintering at 1300 °C in air for 10 h, the 40MCO–60CPO membranes were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), back scattered SEM (BSEM), and energy dispersive X-ray spectroscopy (EDXS), showing that the 40MCO–60CPO composite represents a micro-scale mixture of mainly the two phases MCO and CPO, but small amounts of MnO 2 and (MnCo)(MnCo) 2 O 4− δ were detected in the sintered membranes as well. The oxygen permeation fluxes through the 40MCO–60CPO dual phase membrane were measured at elevated temperatures (900–1000 °C) with one side of the membrane exposed to synthetic air and the other side to a CO 2 /He sweep gas stream. A stable oxygen permeation flux of 0.48 mL cm −2  min −1 was obtained for a 0.3 mm thick membrane under an air/CO 2 oxygen partial pressure gradient at 1000 °C. It was also found that 40MCO–60CPO dual phase membranes are stable for more than 60 h even when pure CO 2 was used as the sweep gas, which recommends 40MCO–60CPO membranes as promising candidates for 4-end membrane operation in an oxy-fuel power plant.