Portarapillo M, Landi G, Luciani G, Imparato C, Vitiello G, Deorsola FA, Aronne A, Di Benedetto A. Redox behavior of potassium doped and transition metal co-doped Ce
0.75Zr
0.25O
2 for thermochemical H
2O/CO
2 splitting.
RSC Adv 2022;
12:14645-14654. [PMID:
35702191 PMCID:
PMC9109714 DOI:
10.1039/d2ra01355j]
[Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 04/27/2022] [Indexed: 11/21/2022] Open
Abstract
CeO2 slow redox kinetics as well as low oxygen exchange ability limit its application as a catalyst in solar thermochemical two-step cycles. In this study, Ce0.75Zr0.25O2 catalysts doped with potassium or transition metals (Cu, Mn, Fe), as well as co-doped materials were synthesized. Samples were investigated by X-ray diffraction (XRD), N2 sorption (BET), as well as by electron paramagnetic resonance (EPR) and X-ray photoelectron spectroscopy (XPS) to gain insight into surface and bulk features, which were connected to redox properties assessed both in a thermogravimetric (TG) balance and in a fixed bed reactor. Obtained results revealed that doping as well as co-doping with non-reducible K cations promoted the increase of both surface and bulk oxygen vacancies. Accordingly, K-doped and Fe-K co-doped materials show the best redox performances evidencing the highest reduction degree, the largest H2 amounts and the fastest kinetics, thus emerging as very interesting materials for solar thermochemical splitting cycles.
Potassium doped and co-doped ceria–zirconia show improved CO2/H2O splitting activity. This holds huge promise for the design of high performance systems for solar thermochemical splitting cycles allowing the production of solar fuels.![]()
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