Tuesday, November 10, 2015: 12:30 PM
250F (Salt Palace Convention Center)
During multiple thermochemical water-splitting cycles for hydrogen generation, redox materials undergo sintering or grain growth. Consequently, stable hydrogen volume generation is not realized. To address this issue, we report core-shell nanoparticle morphology of redox materials, which is anticipated to prevent grain growth. Core-shell nanoparticles were synthesized using sol-gel assisted surfactant templating method. In particular, non-ionic and ionic surfactants were explored for the synthesis of ferrite nanoparticles with porous ceramic shell. The core-shell ferrite nanoparticles were analyzed by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). TEM images confirmed the presence of core-shell morphology with ferrite nanoparticles residing inside the porous ceramic shell. These nanoparticles were loaded inside the Inconel tubular reactor as a packed-bed and regenerated for 2 hours at 1100 deg C under the nitrogen flow. Water-splitting step was also performed at the same temperature of 1100 deg C. To compare sintering or grain growth, ferrite nanoparticles were also immobilized on ceramic support and these materials were investigated for hydrogen generation at water-splitting and regeneration temperatures of 1100 deg C. The hydrogen volume generated by the core-shell nanoparticles was appeared to be relatively similar during multiple thermochemical cycles, however, it was found to be lower as compared to ferrite nanoparticles. The results obtained on the hydrogen volume generated by core-shell nanoparticles and immobilized ferrite nanostructures during multiple thermochemical cycling will be presented.