V. Amar, B. Maddipudi, G. Bauer, R.V. Shende
South Dakota School of Mines and Technology,
Keywords: hydrogen, water-splitting, ferrite nanoparticles, core-shell, immobilization
Summary:Industrial hydrogen production via methane steam reforming process significantly contributes to CO2 emission. Additionally, the production of a hydrogen carrier such as ammonia is also responsible for elevated CO2 level in the atmosphere. From climate change viewpoint, it is critically important to mitigate the CO2 emission. In this study, core-shell and immobilized ferrites nanoparticles were investigated for CO2 free sustainable hydrogen production via thermochemical water-splitting process. The precursors of high temperature refractory ceramic materials such as YSZ, ZrO2 and Y2O3 were used to achieve the core-shell morphology with ferrite nanoparticles whereas highly porous YSZ fiber boards were utilized to immobilize the nanoparticles of a redox material. Surfactant templating assisted sol-gel method was used to prepare core-shell and immobilized morphologies, which were characterized using powdered x-ray diffraction, BET surface area analyzer, SEM/EDX, and TEM. Efficacy of hydrogen production via thermochemical water-splitting process was tested in a semi-continuous tubular packed-bed reactor where multiple thermochemical cycles were performed at 1100 ℃. Oxygen diffusivity in a crystal lattice of redox materials was determined using the electrochemical impedance spectroscopy (EIS). The results obtained with respect to synthesis of core-shell and immobilized ferrite nanoparticles, characterization, hydrogen production in multiple thermochemical cycles, and thermal stabilization aspects will be presented.