Iron(II) molybdate

Iron(II) molybdate
Names
	IUPAC name Iron(II) molybdate
	Other names Iron molybdate
Identifiers
CAS Number	13718-70-2 ;
3D model (JSmol)	Interactive image;
ChemSpider	13795022;
PubChem CID	16217045;
CompTox Dashboard (EPA)	DTXSID30584227 ;
	InChI InChI=1S/Fe.Mo.4O/q+2;;;;2*-1 Key: QQOCLJJWXLOEJE-UHFFFAOYSA-N;
	SMILES [O-][Mo](=O)(=O)[O-].[Fe+2];
Properties
Chemical formula	FeMoO4
Molar mass	215.78 g/mol
Appearance	Dark brown, yellow solid
Density	5.6 g/cm3 (20 °C)
Melting point	1,115 °C (2,039 °F; 1,388 K)
Solubility in water	0.00766 g/100 mL (20 °C) ; 0.038 g/100 mL (100 °C)
Structure
Crystal structure	Monoclinic
Space group	P21 (No. 4)
Lattice constant	a = 15.693 Å, b = 9.235 Å, c = 18.218 Å α = 90°, β = 125.21°, γ = 90°
Thermochemistry
Heat capacity (C)	118.5 J/mol K
Std enthalpy of; formation (ΔfH⦵298)	−1075 kJ/mol
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Iron(II) molybdate is an inorganic compound with the chemical formula FeMoO₄. It is a dark brown to yellow solid forming monoclinic crystals.^[1]^[2]

Synthesis

Iron(II) molybdate is precipitated by the reaction of iron(II) chloride or iron(II) sulfate^[3] and sodium molybdate.

Na₂MoO₄ + FeSO₄ → Na₂SO₄ + FeMoO₄

Na₂MoO₄ + FeCl₂ → 2 NaCl + FeMoO₄

FeMoO₄ has been used as relatively stable active material for anodes in Li-ion batteries for conversion reaction,^[4] as anode material in aqueous supercapacitors due to fast redox reactions^[3] and as catalyst for oxygen evolution in alkaline solutions.^[5]

^ ^a ^b Perry, Dale L. (2016-04-19). Handbook of Inorganic Compounds. CRC Press. p. 215. ISBN 978-1-4398-1462-8.
^ ^a ^b Rapposch, M. H.; Anderson, J. B.; Kostiner, E. (2002-05-01). "Crystal structure of ferric molybdate, Fe2(MoO4)3". ACS Publications. doi:10.1021/ic50213a065. Retrieved 2026-01-25.
^ ^a ^b Senthilkumar, Baskar; Kalai Selvan, Ramakrishnan (2014-07-15). "Hydrothermal synthesis and electrochemical performances of 1.7 V NiMoO4⋅xH2O||FeMoO4 aqueous hybrid supercapacitor". Journal of Colloid and Interface Science. 426: 280–286. doi:10.1016/j.jcis.2014.04.010. PMID 24863794.
^ Zhang, Zhenyu; Li, Wenyue; Ng, Tsz-Wai; Kang, Wenpei; Lee, Chun-Sing; Zhang, Wenjun (2015-10-13). "Iron(ii) molybdate (FeMoO4) nanorods as a high-performance anode for lithium ion batteries: structural and chemical evolution upon cycling". J. Mater. Chem. A. 3 (41): 20527–20534. doi:10.1039/c5ta05723j. ISSN 2050-7496.
^ Singh, R. N.; Singh, J. P.; Singh, A. (2008-08-01). "Electrocatalytic properties of new spinel-type MMoO4 (M = Fe, Co and Ni) electrodes for oxygen evolution in alkaline solutions". International Journal of Hydrogen Energy. 33 (16): 4260–4264. Bibcode:2008IJHE...33.4260S. doi:10.1016/j.ijhydene.2008.06.008.