Chemical looping dry reforming of waste glycerol coupled with thermochemical water splitting cycle by mesoporous Fe2O3-Co3O4/CeO2 oxygen carriers

A coupled chemical looping conversion of glycerol and CO2 with thermochemical water splitting (WS) cycle is substantially researched due to its potential for one-step renewable H2 and syngas production. The major challenge lies on having good controls of redox reactions of the oxygen carriers (OCs) used and its unusual sensitivity to the changes of the compositions, chemical states and structure, etc. Here, we develop the OCs that consists of Fe2O3-Co3O4 supported on the mesoporous CeO2 structure (Fe2O3-Co3O4/CeO2), which simultaneously promote glycerol oxidization (GO), dry reforming of glycerol (GDR), and WS processes. The easy migration and activation of lattice oxygen by Fe2O3-Co3O4/CeO2 greatly improved the GO and GDR to produce syngas at the first step, and the pure H2 production by the reduced Fe2O3-Co3O4/CeO2 achieved excellent WS and oxygen storage at 750℃. The low-content Fe dopant in the OC presented a beneficial effect on the anti-sintering performance, and increase of Co-doping indicated a high activity to WS as well as enhanced GDR. The Fe2O3-Co3O4/CeO2 with 7:5:10 of Co: Fe: Ce molar ratio presented the highest glycerol and CO2 conversions and the highest H2 yield, also illustrated the excellent activity and stability in 40 consecutive redox cycles.