Hydrogen production from chemical looping reforming over Ni/CeO2 nanorod oxygen carrier in a fixed-bed reactor

In this work, a CeO2 nanorods-based oxygen carrier was prepared for hydrogen production from chemical looping steam reforming (CLSR) of ethanol. CeO2 nanorods (NR) served as a support for dispersing Ni particles. The Ni/CeO2 NR oxygen carrier was synthesized by a hydrothermal-impregnation method and characterized by powder X-ray diffraction, Raman spectra, transmission electron microscopy, X-ray photoelectron spectroscopy, and hydrogen temperature-programmed reduction. Transmission electron microscope revealed that nano-sized Ni particles were uniformly loaded on CeO2 NR. The activity and durability of Ni/CeO2 NR oxygen carrier were evaluated in the CLSR process with a fixed-bed tubular reactor. CeO2 NR supported Ni exhibited enhanced activity with a higher ethanol convention and H2 selectivity compared to conventional Ni/Al2O3. Additionally, Ni/CeO2 NR was more resistant to deactivation during the long-term CLSR testing. The high reactivity and durability of Ni/CeO2 NR is mainly attributed to the CeO2 NR support with large specific surface area and {110} and {100} planes which present great superiority for the dispersion of Ni nanoparticles, leading to a strong metal-support interaction effect. Besides, the CeO2 NR possesses high oxygen storage and mobility which is beneficial to the promotion of catalytic activity and removal of carbon deposition.