Partial substitution of B cation in La0.6Sr0.4MnO3 perovskites: A promising strategy to improve the redox properties useful for solar thermochemical water and carbon dioxide splitting. (1st September 2018)

• Record Type: Journal Article
• Authors: Luciani, G.; Landi, G.; Aronne, A.; Di Benedetto, A.
• Is Part Of: Solar energy. Volume 171(2018)
• Page Start: 1
• Page End: 7
• Publication Date: 2018-09-01
• Subjects: Solar thermochemical splitting -- Perovskite -- Hydrogen -- High temperature; Solar energy -- Periodicals; Solar engines -- Periodicals; 621.47
• DOI: 10.1016/j.solener.2018.06.058
• Languages: English
• ISSNs: 0038-092X

Abstract

Graphical abstract: Highlights: Perovskites with Mn and Fe as B cation successfully prepared and tested in STS. Mixed materials show structural features intermediate between pure Mn and Fe perovskites. The presence of Fe improves self-reduction and, therefore, the producible H2 . The presence of Mn improves the oxidation kinetics, lowering typical splitting temperature. Use of diverse B ions as an effective strategy to manage self-reducibility and splitting activity. Abstract: Mixed perovskites, described by the formula La0.6 Sr0.4 Mn1−x Fex O3−δ with x ranging from 0 to 1, were prepared and tested as potential catalysts for the solar thermochemical water and carbon dioxide splitting. The increase of iron amount promotes the reduction step according to the trend of the starting reduction temperatures; on the other hand, the reactivity towards H2 O and CO2 seems to be fostered by high Mn contents. The highest amounts of oxygen evolved during thermogravimetric analysis and hydrogen produced during splitting tests occur to the sample with x = 1 even if a non-monotonic trend with iron substitution is appreciated. Instead, CO amount progressively decreases by increasing iron content. The results reported in this work indicate that the formulation of bi-functional systems with two active sites, one showing good self-reduction the other good reactivity towards splitting reactions, is the best route to prepare materials with larger intrinsic H2 and CO productivity as well as lower reduction/oxidation temperature.