Mixed ionic/electronic conducting ceramic membranes for oxygen-assisted carbon dioxide reforming

Incorporating a SrFeCo0.5Ox (SFC) membrane into a CO2 reforming reactor doubles methane conversion with a powder Pt/ZrO2 catalyst. The deactivation of both Pt/ZrO2 and a Pt/CeZrO2 catalyst is also retarded substantially. Catalyst performance improvement is attributed to a beneficial in situ effect of the SFC membrane on catalyst oxidation state. The SFC membranes exhibit low oxygen flux (< 0.01 sccm/cm2) and insignificant methane conversion activity. The molecular-level effects of SFC membranes, co-fed gas-phase oxygen, and conventional powder catalyst oxidation state are all assessed using reactor effluent composition trends. A novel single parameter (the Oxidation Factor) is proposed for evaluating product selectivity for CO2 reforming in the presence of oxygen.;Membrane oxygen release is attributed entirely to hydrogen oxidation on the membrane surface under these reforming reaction conditions. This claim contradicts a long-standing assumption in the literature that membrane oxygen participates in reforming reactions as molecular oxygen.