Microwave Synthesis of High Activity FeSe2/C Catalyst toward Oxygen Reduction Reaction

Abstract

Abstract:The carbon supported iron selenide catalysts (FeSe2/C) were prepared with various selenium to iron ratios (Se/Fe), namely, Se/Fe = 2.0, 2.5, 3.0, 3.5 and 4.0, through facile microwave route by using ferrous oxalate (FeC2O4·2H2O) and selenium dioxide (SeO2) as precursors. Accordingly, effects of Se/Fe ratio on the crystal structure, crystallite size, microstructure, surface composition and electrocatalytic activity for oxygen reduction reaction (ORR) of FeSe2/C in an alkaline medium were systematically investigated. The results revealed that all the FeSe2/C catalysts obtained with the Se/Fe ratios of 2.0-4.0 exhibited almost pure orthogonal FeSe2 structure with the estimated mean crystallite sizes of 32.9-36.2 nm. The electrocatalytic activities in potassium hydroxide solutions were higher than those in perchloric acid solutions, and two peak potentials or two plateaus responded to ORR were observed from cyclic voltammograms and polarization curves, respectively. The ORR potentials of 0.781-0.814 V with the electron transfer numbers of 3.3-3.9 at 0.3 V could be achieved as the Se/Fe ratios varied from 2.0 to 4.0. The Fe and Se were presented at the surface of FeSe2/C upon further reduction on FeSe2. The Se/Fe ratios slightly influenced the degree of graphitization in carbon support and the amount of active sites for ORR. OPEN ACCESSCatalysts 2015, 5 1080

Preparation of Hollow Fe2O3 Nanorods and Nanospheres by Nanoscale Kirkendall Diffusion, and Their Electrochemical Properties for Use in Lithium-Ion Batteries

“…4b, signals were observed at binding energies of 54.5 and 55.3 eV, corresponding to Se 3d 5/2 and Se 3d 3/2 , respectively. Signals corresponding to the oxidized-Se (Se-O) and metalloid Se (Se-Se) bonds were also observed in the XPS spectrum of Se, with the former due to the partial oxidation of metalloid Se under atmospheric conditions, and the latter likely due to the deposition of small amounts of metalloid Se within the porous carbon nanofiber during the selenization process39. Furthermore, in the C 1 s XPS spectrum (Fig.…”

“…In the Fe 2p spectrum shown in Fig. 4a, the main peaks were observed at the characteristic FeSe binding energies of 710.2 eV (Fe 2p 3/2 ) and 724.1 eV (Fe 2p 1/2 )383940. In addition, in the Se 3d spectrum shown in Fig.…”

From a Molecular 2Fe‐2Se Precursor to a Highly Efficient Iron Diselenide Electrocatalyst for Overall Water Splitting

“…[6a] In the XPS spectra (Supporting Information, Figure S30), the Fe 2p 3/2 of as ample subjected to OER by CV showed ap eak at 710.7 eV,w hile as ample subjected to OER by CP exhibited ap eak at 711 eV, indicating an increase in the oxidation state of Fe from mixed Fe 2+ /Fe 3+ to Fe 3+ . [18,23] Additionally,the XPS analysis revealed the loss of surface Se (ca. [17,22] TheS e3dp eaks were slightly shifted from the initial spectrum and am inor peak at about 58.3 eV suggests oxidation of the selenium surface (Supporting Information, Figure S31).…”

Electrocatalysis in Fuel Cells

“…Non-noble metal oxides and chalcogenides are also promising catalysts for ORR. Some interesting works on the synthesis and evaluation of Ti-Nb oxides [15], CoS [16] and FeSe2 [17] were also included in this Special Issue.…”