Nano-Scale Cobalt Ferrite and Nickel Ferrite On High Surface Area ZrO2 Particles for Chemical Looping Hydrogen Production

The chemical looping hydrogen production process uses synthesis gas or methane to reduce a metal oxide material, forming a waste stream of CO₂ and H₂O from which CO₂ can be easily sequestered.  The reduced metal oxide is then oxidized with steam to produce pure H₂ and regenerate the original metal oxide.  This system requires a metal oxide material that can achieve high H₂ and CO conversions to H₂O and CO₂ during the reduction step while maintaining fast oxidation and reduction kinetics that do not degrade over time.  In this study, the use of nano-scale cobalt- and nickel-ferrite (CoFe₂O₄ and NiFe₂O₄) based materials was investigated for chemical looping hydrogen production.  Nano-thin films of ferrite were deposited on a high surface area ZrO₂ support material using the atomic layer deposition (ALD) process to minimize sintering and diffusion limitations on reaction kinetics.  The kinetics and cyclability performance of these thin film materials were analyzed and compared with the performance of conventionally made impregnation ferrite samples.