Research Article pubs.acs.org/journal/ascecg
Iron Oxide with Facilitated O2− Transport for Facile Fuel Oxidation and CO2 Capture in a Chemical Looping Scheme Nathan L. Galinsky, Yan Huang, Arya Shafiefarhood, and Fanxing Li* Department of Chemical and Biomolecular Engineering, North Carolina State University, 911 Partners Way, Raleigh, North Carolina 27695-7905, United States S Supporting Information *
ABSTRACT: The chemical looping strategy offers a potentially viable option for efficient carbonaceous fuel conversion with a reduced carbon footprint. In the chemical looping process, an oxygen carrier is reduced and oxidized in a cyclic manner to convert a carbonaceous fuel into separate streams of concentrated carbon dioxide and carbon-free products such as electricity and/ or hydrogen. The reactivity and chemical and physical stability of the oxygen carrier are of pivotal importance to chemical looping processes. A typical oxygen carrier is composed of a multi-valence transition metal oxide supported on an “inert” support. Although the support does not get reduced or oxidized at any significant extent, numerous studies have indicated that certain supports such as TiO2 and Al2O3 can improve oxygen carrier stability and/or reactivity. This study reports the use of mixed ionic−electronic conductive support in iron-based oxygen carriers. By incorporating a perovskite-based mixed conductive support such as lanthanum strontium ferrite (LSF), the reactivity of the oxygen carrier is enhanced by 5−70 times when compared to oxygen carriers with conventional TiO2-, Al2O3-, or yttria-stabilized zirconia (YSZ) support. The mixed conductivity enhanced oxygen carrier also shows good stability and coke resistance. Characterization studies indicate that the enhanced oxygen carrier is composed of intermixed nanoscale (
