Co-precipitation synthesized nanostructured Ce0.9Ln0.05Ag0.05O2−δ materials for solar thermochemical conversion of CO2 into fuels

Synthesis, characterization, and application of Ce0.9Ln0.05Ag0.05O2−δ materials (where, Ln = La, Pr, Nd, Sm, Gd, Tb, Dy, Er) for the thermochemical conversion of CO2 reported in this paper. The Ce0.9Ln0.05Ag0.05O2−δ materials were synthesized by using an ammonium hydroxide-driven co-precipitation method. The derived Ce0.9Ln0.05Ag0.05O2−δ materials were characterized via powder X-ray diffraction, scanning electron microscope, and electron diffraction spectroscopy. The characterization results indicate the formation of spherically shaped Ce0.9Ln0.05Ag0.05O2−δ nanostructured particles. As-prepared Ce0.9Ln0.05Ag0.05O2−δ materials were further tested toward multiple CO2 splitting cycles by utilizing a thermogravimetric analyzer. The results obtained indicate that all the Ce0.9Ln0.05Ag0.05O2−δ materials produced higher quantities of O2 and CO than the previously studied pure CeO2 and lanthanide-doped ceria materials. Overall, the Ce0.911La0.053Ag0.047O1.925 showed the maximum redox reactivity in terms of O2 release (72.2 μmol/g cycle) and CO production (136.6 μmol/g cycle).Other Information Published in: Journal of Materials Science License: https://creativecommons.org/licenses/by/4.0See article on publisher's website: http://dx.doi.org/10.1007/s10853-020-04567-w</p

Ni incorporation in MgFe2O4 for improved CO2-splitting activity during solar fuel production

Efficacy of the sol–gel derived Ni-doped Mg-ferrites for an enhanced CO2 splitting activity is investigated. The results allied with the characterization indicate the formation of nominally phase pure Ni-doped Mg-ferrites with a coarser particle morphology. Ni-doped Mg-ferrites are further tested for multiple thermal reduction as well as CO2 splitting steps by using a thermogravimetric analyzer. The results associated with the thermogravimetric analysis confirmed that most of the Ni-doped Mg-ferrites attained a steady TR aptitude after crossing the 5th or 6th cycle. Likewise, the CS capability of all the Ni-doped Mg-ferrites accomplished consistency after 4th cycle (except for Ni0.11Mg0.88Fe2.01O4.005). The Ni0.90Mg0.11Fe2.04O4.070 showed the highest amount of O2 release (117.1 μmol/g cycle) and CO production (210.3 μmol/g cycle) in ten consecutive thermochemical cycles. Besides, Ni0.29Mg0.72Fe1.98O3.980 indicated better re-oxidation aptitude ($$n_{\text{CO}} /n_{{{\text{O}}_{2} }}$$nCO/nO2 ratio = 1.89) when compared with other Ni-doped Mg-ferrites.Other Information Published in: Journal of Materials Science License: https://creativecommons.org/licenses/by/4.0See article on publisher's website: http://dx.doi.org/10.1007/s10853-020-04794-1</p

Application of Li-, Mg-, Ba-, Sr-, Ca-, and Sn-doped ceria for solar-driven thermochemical conversion of carbon dioxide

The redox reactivity of the Li-, Mg-, Ca-, Sr-, Ba-, and Sn-doped ceria (Ce0.9A0.1O2−δ) toward thermochemical CO2 splitting is investigated. Proposed Ce0.9A0.1O2−δ materials are prepared via co-precipitation of the hydroxide technique. The composition, morphology, and the average particle size of the Ce0.9A0.1O2−δ materials are determined by using suitable characterization methods. By utilizing a thermogravimetric analyzer setup, the long-term redox performance of each Ce0.9A0.1O2−δ material is estimated. The results obtained indicate that all the Ce0.9A0.1O2−δ materials are able to produce steady amounts of O2 and CO from cycle 4 to cycle 10. Based on the average $$n_{{{\text{O}}_{2} }}$$nO2 released and $$n_{\text{CO}}$$nCO produced, the Ce0.899Sn0.102O2.002 and Ce0.895Ca0.099O1.889 are observed to be the top and bottom-most choices. When compared with the CeO2 material, all Ce0.9A0.1O2−δ materials showed elevated levels of O2 release and CO production.Other Information Published in: Journal of Materials Science License: https://creativecommons.org/licenses/by/4.0See article on publisher's website: http://dx.doi.org/10.1007/s10853-020-04875-1</p