Iron-Doped BaMnO3 for Hybrid Water Splitting and Syngas Generation

5 years ago

Iron-Doped BaMnO3 for Hybrid Water Splitting and Syngas Generation

Amit Mishra, Feng He, Fanxing Li, Vasudev Pralhad Haribal

A rationalized strategy to optimize transition-metal-oxide-based redox catalysts for water splitting and syngas generation through a hybrid solar-redox process is proposed and validated. Monometallic transition metal oxides do not possess desirable properties for water splitting; however, density functional theory calculations indicate that the redox properties of perovskite-structured BaMnxFe1−xO3−δ can be varied by changing the B-site cation compositions. Specifically, BaMn0.5Fe0.5O3−δ is projected to be suitable for the hybrid solar-redox process. Experimental studies confirm such predictions, demonstrating 90 % steam-to-hydrogen conversion in water splitting and over 90 % syngas yield in the methane partial-oxidation step after repeated redox cycles. Compared to state-of-the-art solar-thermal water-splitting catalysts, the rationally designed redox catalyst reported is capable of splitting water at a significantly lower temperature and with ten-fold increase in steam-to-hydrogen conversion. Process simulations indicate the potential to operate the hybrid solar-redox process at a higher efficiency than state-of-the-art hydrogen and liquid-fuel production processes with 70 % lower CO2 emissions for hydrogen production Perovskite power: BaMn0.5Fe0.5O3−δ demonstrates over 90 % water-splitting conversion and over 90 % syngas-yield using a hybrid solar-redox process. Computational modelling, fluidized-bed experiments, and in situ XRD analysis indicate that perovskite BaMn0.5Fe0.5O3−δ is ideal for the proposed redox reactions. Process simulations indicate a 70 % reduction in CO2 emissions for hydrogen production compared to the current state-of-the-art processes.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/cssc.201700699