Synergistic improvements in stability and performance of the double perovskite-type oxides La2−xSrxFeCoO6 for chemical looping steam methane reforming

Kun Zhao, Luwei Li, Anqing Zheng, Zhen Huang, Fang He, Yang Shen, Guoqiang Wei, Haibin Li and Zengli Zhao

Applied Energy, 2017, vol. 197, issue C, 393-404

Abstract: Chemical looping steam methane reforming (CL-SMR) is a potential route to efficiently co-produce syngas and hydrogen. Development of oxygen carrier with high activity, good recyclability, strong resistance to carbon deposition and excellence capacity for steam splitting is highly desired for this process. The article investigated a novel and unique structure of double perovskite-type oxides La1−xSrxFeCoO6 (x=0, 0.2, 0.4, 0.6, 0.8, 1.0) as oxygen carrier. XRD, XPS and H2-TPR technologies were adopted to characterize the physical and chemical properties of them. Meanwhile, isothermal reactions and cyclic redox reactions were carried out in a fixed-bed reactor to determine the influences of Sr-substitution on the reactivity of La1−xSrxFeCoO6. XRD results confirmed the formation of double perovskite crystal structure for all the samples, while substitution of Sr induced a certain degree of Fe/Co disorder generating oxygen vacancies and/or higher oxidation states of metal cations. Synergistic interactions between surface metal ions, such as Fe4+/Fe5+ with Co3+ which were detected by XPS, strongly enhance the reducibility of oxygen carriers. Three zones including total oxidation of methane by surface oxygen, partial oxidation of methane by lattice oxygen and carbon deposition were divided. Among the six samples with different substitution of Sr, La0.6Sr0.4FeCoO6 exhibited the best oxygen transport ability, thermal stability, as well as capacity for hydrogen generation. A stable CH4 conversion at ∼90% with desired H2/CO ratio at 2.0–2.5 in the methane reduction stage, and an average hydrogen yield at ∼5.9mmol/g oxygen carrier with ∼93.8% of hydrogen concentration in the steam oxidation stage were obtained during twenty successive redox reactions, which made them very attractive for the purpose of chemical looping partial oxidation of carbon fuel in real applications.

Keywords: Chemical looping; Methane reforming; Double perovskite; Synergistic effect; Oxygen vacancy (search for similar items in EconPapers)
Date: 2017
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (10)

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0306261917304464
Full text for ScienceDirect subscribers only

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:appene:v:197:y:2017:i:c:p:393-404

Ordering information: This journal article can be ordered from
http://www.elsevier.com/wps/find/journaldescription.cws_home/405891/bibliographic
http://www.elsevier. ... 405891/bibliographic

DOI: 10.1016/j.apenergy.2017.04.049

Access Statistics for this article

Applied Energy is currently edited by J. Yan

More articles in Applied Energy from Elsevier
Bibliographic data for series maintained by Catherine Liu ().