A novel thermally stable Fe 2 O 3 /Al 2 O 3 nanofiber-based oxygen carrier for chemical-looping combustion

Fe 2 O 3 -Al 2 O 3 composite metal oxides have been extensively used as oxygen carriers in chemical-looping combustion as they are abundantly available, low cost and less toxic in nature. Severe sintering at high temperatures is a major concern for these oxygen carriers which adversely effects the cyclic stability and life. In this work, novel Fe 2 O 3 -Al 2 O 3 composite nanofibers synthesized by electrospinning are proposed as the oxygen carriers with remarkable thermal cyclic stability. Morphology and microstructural changes of these nanofibers are investigated after 1st and 20th thermal cycles. These nanofiber metal oxides exhibited excellent sintering resistance and maintained entangled fibrous morphology as compared to non-fibrous metal oxides. The sintering resistance of composite nanofibers and nanoparticles is further analyzed in chemical-looping combustion (CLC) environment using CO as fuel. Sintering of composite nanoparticles with clear morphological changes is noticed after five redox cycles whereas the nanofibers retained their fibrous structure and did not sinter.