Solar-Driven Redox Splitting of CO2 Using 3D-Printed Hierarchically Channeled Ceria Structures
Abstract
Fuel produced from CO2 and H2O using solar energy can contribute to making aviation more sustainable. Particularly attractive is the thermochemical production pathway via a ceria-based redox cycle, which uses the entire solar spectrum as the source of high-temperature process heat to directly produce a syngas mixture suitable for synthetizing kerosene. However, its solar-to-fuel energy efficiency is hindered by the inadequate isotropic topology of the ceria porous structure, which fails to absorb the incident concentrated solar radiation within its entire volume. Here we design and 3D-print hierarchically channeled structures of pure ceria by Direct Ink Writing (DIW) to enable volumetric radiative absorption while maintaining high effective densities required for maximizing the fuel yield. The complex interplay between radiative heat transfer and thermochemical reaction was investigated in a solar thermogravimetric analyzer with samples exposed to high-flux irradiation, mimicking realistic operation of solar reactors. Channeled structures with a stepwise optical thickness achieved a higher and more uniform temperature profile compared to that of state-of-art isotropic structures, doubling the volume-specific fuel yield for the same solar flux input. Thermomechanical stability of the ceria graded structures, DIW-printed using a novel ink formulation with optimal rheological behaviour, was validated by performing 100 consecutive redox cycles. Show more
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https://doi.org/10.3929/ethz-b-000626644Publication status
publishedExternal links
Journal / series
Advanced Materials InterfacesVolume
Pages / Article No.
Publisher
Wiley-VCHSubject
3D printing; CERAMIC MATERIALS; solar fuels; Solar reactor; thermochemical cycles; Porous structures; Concentrated solar energy; CO2 splitting; H2O splitting; Hierarchical structure; Radiative transferOrganisational unit
03530 - Steinfeld, Aldo / Steinfeld, Aldo
03831 - Studart, André R. / Studart, André R.
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