Synthesis of Ca0.8Sr0.2Ti0.7Fe0.3O3 − δ thin film membranes and its application to the partial oxidation of methane

We propose the preparation of thin films on the porous substrate using one component Ca0.8Sr0.2Ti0.7Fe0.3O3 − δ (CTO) perovskite-type oxide with the same composition, prepared by using different procedures. An asymmetric membrane with a 20 μm thickness was prepared by using CTO synthesized by the supercritical hydrothermal synthesis method. This asymmetric membrane was used as a one component membrane reactor (OCMR) comprising the membrane and the partial oxidation catalyst (Ni supported on Ca0.8Sr0.2Ti0.9Fe0.1O3 − δ) to produce synthesis gas from methane. The performance of OCMR has been investigated for the partial oxidation of methane in synthesis gas in natural gas conversion process. For this OCMR, the conversions of methane and selectivity to CO were 82.3% and 99.8% at 1173 K, respectively, and were significantly improved compared with the unsupported solid disk type membrane with a 500 μm thickness. Moreover, the activation energy of the oxygen permeation process and the relationship between oxygen permeation and film thickness were confirmed to investigate oxygen permeation properties of the CTO thin film under OCMR.

► A thin dense film of CTO perovskite-type oxide was prepared on a porous substrate.
► Fine supercritical hydrothermal -CTO nanoparticles were used as membrane material.
► The thinnest membrane thickness was about 20 μm.
► The performance of OCMR in the partial oxidation of methane was confirmed.
► The CH4 conversion and O2 permeation were significantly improved.