Designed porous microstructures for electrochemical reduction of bulk hematite ceramics

authors	Ivanova, YA; Monteiro, JF; Teixeira, LB; Vitorino, N; Kovalevsky, AV; Frade, JR
nationality	International
journal	MATERIALS & DESIGN
author keywords	Cellular ceramics; Porosity; Cathodic reduction; Hematite; Ceramic cathode
keywords	PARAFFIN EMULSIFIED SUSPENSIONS; CELLULAR CERAMICS; CATHODIC REDUCTION; ALKALINE-SOLUTION; PASSIVE FILMS; IRON; PARTICLES; MAGNETITE; TEMPERATURES; ELECTROLYSIS
abstract	This work proposes a new approach for electrochemical reduction of hematite to magnetite and/or metallic iron, based on ceramic cathodes with designed microstructures. The processing method, involving emulsification of concentrated aqueous ceramic suspensions with melted paraffin, enables preparation of cellular hematite ceramics possessing open porosity and pore interconnectivity controlled by simple process parameters. The obtained porous hematite ceramics were successfully used as cathodes for in situ electrochemical reduction in aqueous alkaline electrolyte. Electrochemical reduction converts the designed ceramic microstructure to corresponding cellular Fe/Fe(3)0(4)/Fe(2)0(3) composites with adjustable phase distributions and high prospects for applications in heterogeneous catalysis or other applications, based on unique combinations of active functionalities of metallic Fe, magnetite and hematite. (C) 2017 Elsevier Ltd. All rights reserved.
publisher	ELSEVIER SCI LTD
issn	0264-1275
isbn	1873-4197
year published	2017
volume	122
beginning page	307
ending page	314
digital object identifier (doi)	10.1016/j.matdes.2017.03.031
web of science category	Materials Science, Multidisciplinary
subject category	Materials Science
unique article identifier	WOS:000400213200029