Skip to main content
SpringerLink
Log in

Thermal decomposition of ammonium molybdates

  • Published:
Journal of Thermal Analysis and Calorimetry Aims and scope Submit manuscript

Abstract

The thermal behavior of ammonium molybdates, i.e., (NH4)6Mo7O24·4H2O (1) and (NH4)2MoO4 (2), was studied in inert (N2) and oxidizing (air) atmospheres by TG/DTA-MS, XRD, FTIR and SEM. The thermal decomposition sequence of 2 had similarities to 1; however, there were significant differences as well. When both of them were annealed, NH3 and H2O were released parallel, and in air the as-evolved NH3 was burnt partially into NO and N2O. In both atmospheres, while 1 decomposed in four steps, the thermal decomposition of 2 involved 5 steps. In the case of 1, the intermediate products were (NH4)8Mo10O34, (NH4)2Mo4O13 and h-MoO3. In contrast, the decomposition intermediates of 2 were (NH4)2Mo3O10, (NH4)2Mo2O7, (NH4)2Mo4O13 and h-MoO3. By both 1 and 2, the final product was dominated by o-MoO3, accompanied with small amount of Mo4O11 in N2, which was absent in air. Most decomposition steps were endothermic, except for the last step around 400 °C, where crystallization from the residual amorphous phase had an exothermic heat effect. In addition, the combustion of NH3 also changed the DTA curve into exothermic in some cases. The morphology of the final products was characterized by 1–5 μm sheet-like particles, except for annealing 2 in N2, when 0.5- to 1-μm-thick and 5- to 10-μm-long needle-shaped particles were detected.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13
Fig. 14

Similar content being viewed by others

References

  1. Liu H, Liu C, Yin C, Chai Y, Li Y, Liu D, Liu B, Li X, Wang Y, Li X. Preparation of highly active unsupported nickel–zinc–molybdenum catalysts for the hydrodesulfurization of dibenzothiophene. Appl Catal B. 2015;174–175:264–76.

    Article  Google Scholar 

  2. Adamiak J. Controlled nitration of anisole over HNO3/PO4/MoO3/SiO2/solvent systems. J Mol Catal A. 2015;407:81–6.

    Article  CAS  Google Scholar 

  3. Ressler T, Walter A, Huang ZD, Bensch W. Structure and properties of a supported MoO3–SBA-15 catalyst for selective oxidation of propene. J Catal. 2008;254:170–9.

    Article  CAS  Google Scholar 

  4. Grasselli RK. Advances and future trends in selective oxidation and ammoxidation catalysis. Catal Today. 1999;49:141–53.

    Article  CAS  Google Scholar 

  5. Haber J, Lalik E. Catalytic properties of MoO3 revisited. Catal Today. 1997;33:119–37.

    Article  CAS  Google Scholar 

  6. Zaman S, Smith K. A review of molybdenum catalysts for synthesis gas conversion to alcohols: catalysts, mechanisms and kinetics. Catal Rev Sci Eng. 2012;54:41–132.

    Article  CAS  Google Scholar 

  7. Kim HG, Lee KH, Lee JS. Carbon monoxide hydrogenation over molybdenum carbide catalysts. Res Chem Intermed. 2000;26:427–43.

    Article  CAS  Google Scholar 

  8. Saji VS, Lopatin SI, editors. Molybdenum and its compounds: applications, electrochemical properties and geological implications. New York: Nova Science Publishers; 2014.

    Google Scholar 

  9. Hegedűs AJ, Sasvári K, Neugebauer J. Thermo- und röntgenanalytischer Beitrag zur Reduktion des Molybdäntrioxyds und zur Oxydation bzw. Nitrierung des Molybdäns. Z Anorg Allg. Chemie. 1957;293:56–83.

    Google Scholar 

  10. Onchi M, Ma E. An application of the omegatron mass spectrometer to thermal decomposition studies. J Phys Chem. 1963;67:2240–1.

    Article  CAS  Google Scholar 

  11. Ma E. Thermal decomposition of ammonium polymolybdates I. Bull Chem Soc Jpn. 1964;37:171–5.

    Article  CAS  Google Scholar 

  12. Ma E. Thermal decomposition of ammonium polymolybdates II. Bull Chem Soc Jpn. 1964;37:648–53.

    Article  CAS  Google Scholar 

  13. Schwing-Weill MJ. Bull Soc Chim Fr. 1967;10:3795–8.

    Google Scholar 

  14. Kiss AB, Gadó P, Asztalos I, Hegedűs AJ. Acta Chim Acad Sci Hung. 1970;66:235–49.

    CAS  Google Scholar 

  15. Louisy A, Dunoyer JM. Thermal decomposition of ammonium paramolybdate. Bull Soc Chim Fr. 1970;67:1390–4.

    CAS  Google Scholar 

  16. Bhatnagar IK, Chakrabarty DK, Biswas AB. Thermal decomposition of ammonium vanadate, ammonium molybdate, and ammonium tungstate. Indian J Chem. 1972;10:1025–8.

    CAS  Google Scholar 

  17. Hanafi ZM, Khilla MA, Askar MH. The thermal decomposition of ammonium heptamolybdate. Thermochim Acta. 1981;45:221–32.

    Article  CAS  Google Scholar 

  18. Isa K, Ishimura H. Thermal decomposition studies of ammonium heptamolybdate(6-) tetrahydrate by means of high-temperature oscillating x-ray diffraction with a rotating anode type large capacity generator. Bull Chem Soc Jpn. 1981;54:3628–34.

    Article  CAS  Google Scholar 

  19. Topic M, Mogus-Milankovic A. A multiple thermal-analysis of ammonium heptamolybdate tetrahydrate. Chroatica Chem Acta. 1984;57:75–83.

    CAS  Google Scholar 

  20. Sharma IB, Batra S. Characterization and thermal investigations of ammonium heptamolybdate. J Therm Anal. 1987;34:1273–81.

    Article  Google Scholar 

  21. Yong WJ. The GC study of the thermal decomposition of ammonium paramolybdate tetrahydrate in a hydrogen atmosphere. Thermochim Acta. 1990;158:183–6.

    Article  Google Scholar 

  22. Shashkin DP, Shiryaev PA, Kutyrev MY, Krylov OV. Peculiarities of the effect of vanadium ions on molybdena development under prereaction conditions. Kin Catal. 1993;34:302–6.

    Google Scholar 

  23. Halawy SA, Mohamed MA. Characterization of unsupported molybdenum oxide—cobalt oxide catalysts. J Chem Tech Biotechnol. 1993;58:237–45.

    Article  CAS  Google Scholar 

  24. Said AA, Halawy SA. Effects of alkali metal ions on the thermal decomposition of ammonium heptamolybdate tetrahydrate. J Therm Anal. 1994;41:1075–90.

    Article  CAS  Google Scholar 

  25. Said AA. Mutual influences between ammonium heptamolybdate and g-alumina during their thermal treatments. Thermochim Acta. 1994;236:93–104.

    Article  CAS  Google Scholar 

  26. Cabello CI, Botto IL, Thomas HJ. Reducibility and thermal behavior of some Anderson phases. Thermochim Acta. 1994;232:183–93.

    Article  CAS  Google Scholar 

  27. Bi M, Li H, Pan WP, Lloyd WG, Davis BH. Thermal studies of (NH4)2Cr2O7, (NH4)2WO4 and (NH4)6Mo7O24·4H2O deposited on ZrO2. Thermochima Acta. 1996;284:153–60.

    Article  CAS  Google Scholar 

  28. Valmalette JC, Houriet R, Hofmann H, Gavarri JR. Formation of N2O during the thermal decomposition of ammonium salts (NH4)aMxOy (M = V, Cr, Mo and W). Eur J Solid State Inorg Chem. 1997;34:317–29.

    CAS  Google Scholar 

  29. Li JL, Inui T. Characterization of precursors of methanol synthesis catalysts, copper/zinc/aluminum oxides, precipitated at different pHs and temperatures. Appl Catal A. 1996;137:105–17.

    Article  CAS  Google Scholar 

  30. Zhoulan Y, Xinhai L, Qiyuan C. Study on the kinetics of the thermal decompositions of ammonium molybdates. Thermochim Acta. 2000;352–353:107–10.

    Article  Google Scholar 

  31. Thomazeau C, Martin V, Afanasiev P. Effect of support on the thermal decomposition of (NH4)6Mo7O24·4H2O in the inert gas atmosphere. Appl Cat A. 2000;199:61–72.

    Article  CAS  Google Scholar 

  32. Shaheen WM, Selim MM. Thermal decompositions of pure and mixed manganese carbonate and ammonium molybdate tetrahydrate. J Therm Anal Calorim. 2000;59:961–70.

    Article  CAS  Google Scholar 

  33. Murugan R, Chang H. Thermo-Raman investigations on thermal decomposition of (NH4)6Mo7O24·4H2O. J Chem Soc, Dalton Trans. 2001;20:3125–32.

    Article  Google Scholar 

  34. Shaheen WM. Thermal behaviour of pure and binary basic nickel carbonate and ammonium molybdate systems. Mater Lett. 2002;52:272–82.

    Article  CAS  Google Scholar 

  35. Wienold J, Jentoft RE, Ressler T. Structural investigation of the thermal decomposition of ammonium heptamolybdate by in situ XAFS and XRD. Eur J Inorg Chem. 2003; 1058–1071.

  36. Radwan NRE, Mokhtar M, El-Shobaky GA. Thermal behaviour of ammonium molybdate-basic magnesium carbonate system doped with lithium nitrate. J Therm Anal Calorim. 2003;71:977–86.

    Article  CAS  Google Scholar 

  37. Manukyan K, Davtyan D, Bossert J, Kharatyan S. Direct reduction of ammonium molybdate to elemental molybdenum by combustion reaction. Chem Eng J. 2011;168:925–30.

    Article  CAS  Google Scholar 

  38. Biedunkiewicz A, Krawczyk M, Gabriel-Polrolniczak U, Figiel P. Analysis of (NH4)6Mo7O24·4H2O thermal decomposition in argon. J Therm Anal Calorim. 2014;116:715–26.

    Article  CAS  Google Scholar 

  39. Gaigneaux EM, Genet MJ, Ruiz P, Delmon B. Catalytic behavior of molybdenum suboxides in the selective oxidation of isobutene to methacrolein. J Phys Chem B. 2000;104:5724–37.

    Article  CAS  Google Scholar 

  40. Sebenik RF, Burkin AR, Dorfler RR, Laferty JM, Leichtfried G, Meyer-Grünow H, Mitchell PCH, Vukasovich MS, Church DA, Van Riper GG, Gilliland JC, Thielke SA. Molybdenum and Molybdenum Compounds. In Ullmann’s Encyclopedia of Chemical Technology. Weinheim: Wiley-VCH; 2005.

  41. Alizadeh S, Hassanzadeh-Tabrizi SA. Ceram Int. 2015;41:10839–43.

    Article  CAS  Google Scholar 

  42. Szilágyi IM, Madarász J, Hange F, Pokol G. Partial thermal reduction of ammonium paratungstate tetrahydrate. J Therm Anal Calorim. 2007;88:139–44.

    Article  Google Scholar 

  43. Hunyadi D, Sajó I, Szilágyi IM. Structure and thermal decomposition of ammonium metatungstate. J Therm Anal Calorim. 2014;116:329–37.

    Article  CAS  Google Scholar 

  44. Chianga TH, Hob PY, Chiub SY, Chaob AC. Synthesis, characterization and photocatalytic activity of α–MoO3 particles utilizing different polyol monomers under visible light irradiation. J Alloy Comp. 2015;651:106–13.

    Article  Google Scholar 

  45. Szilágyi IM, Santala E, Heikkilä M, Kemell M, Nikitin T, Khriachtchev L, Räsänen M, Ritala M, Leskelä M. Thermal study on electrospun polyvinylpyrrolidone/ammonium metatungstate nanofibers: optimising the annealing conditions for obtaining WO3 nanofibers. J Therm Anal Calorim. 2011;105:73–81.

    Article  Google Scholar 

  46. Madarász J, Szilágyi IM, Hange F, Pokol G. Comparative evolved gas analyses (TG-FTIR, TG/DTA-MS) and solid state (FTIR, XRD) studies on thermal decomposition of ammonium paratungstate tetrahydrate (APT) in air. J Anal Appl Pyrol. 2004;72:197–201.

    Article  Google Scholar 

  47. Szilágyi IM, Madarász J, Pokol G, Király P, Tárkányi G, Saukko S, Mizsei J, Tóth AL, Szabó A, Varga-Josepovits K. Stability and controlled composition of hexagonal WO3. Chem Mater. 2008;20:4116–25.

    Article  Google Scholar 

  48. Range KJ, Zintl R. The thermal decomposition of ammonium metavanadate(V) in open and closed systems. Z Naturforsch. 1988;43:309–17.

    CAS  Google Scholar 

  49. Kótai L, Sajó IE, Jakab E, Keresztury G, Németh C, Gács I, Menyhárd A, Kristóf J, Hajba L, Petrusevski VM, Ivanovski V, Timpu D, Sharma PK. Studies on the chemistry of [Cd(NH3)4](MnO4)2. A low temperature synthesis route of the CdMn2O4+x Type NOx and CH3SH sensor precursors. Z Anorg Allg Chem. 2012;638:177–86.

    Article  Google Scholar 

  50. Kótai L, Gács I, Sajó IE, Sharma PK, Banerji KK. Beliefs and facts in permanganate chemistry – an overview on the synthesis and the reactivity of simple and complex permanganates. Trend Inorg Chem. 2009;11:25–104.

    Google Scholar 

  51. Kótai L, Baneri KK, Sajo IE, Kristóf J, Sreedhar B, Holly S, Keresztury G, Rockenbauer A. An unprecedented-type intramolecular redox reaction of Solid Tetraamminecopper(2+) Bis(permanganate) ([Cu(NH3)4](MnO4)2): a low-temperature synthesis of copper dimanganese tetraoxide-type (CuMn2O4) nanocrystalline catalyst precursors. Helvet Chim Acta. 2002;85:2316–27.

    Article  Google Scholar 

  52. Sajo IE, Kótai L, Keresztury G, Gács I, Pokol G, Kristóf J, Soptrayanov B, Petrusevski VM, Timpu D, Sharma PK. Studies on the chemistry of tetraamminezinc(II) Dipermanganate ([Zn(NH3)4](MnO4)2): low-temperature synthesis of the manganese zinc oxide (ZnMn2O4) catalyst precursor. Helvet Chim Acta. 2008;91:1646–58.

    Article  CAS  Google Scholar 

  53. Hunyadi D, Ramos ALVM, Szilágyi IM. Thermal decomposition of ammonium tetrathiotungstate. J Therm Anal Calorim. 2015;120:209–2015.

    Article  CAS  Google Scholar 

Download references

Acknowledgements

I. M. Szilágyi thanks for a János Bolyai Research Fellowship of the Hungarian Academy of Sciences. An OTKA-PD-109129 grant is acknowledged.

Author information

Authors and Affiliations

  1. Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Szt. Gellért tér 4., 1111, Budapest, Hungary

    Teodóra Nagyné Kovács, Dávid Hunyadi, Alex Leandro Andrade de Lucena & Imre Miklós Szilágyi

  2. MTA-BME Technical Analytical Chemistry Research Group, Hungarian Academy of Sciences, Szt. Gellért tér 4., 1111, Budapest, Hungary

    Imre Miklós Szilágyi

Authors
  1. Teodóra Nagyné Kovács
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Dávid Hunyadi
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Alex Leandro Andrade de Lucena
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Imre Miklós Szilágyi
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Imre Miklós Szilágyi.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Kovács, T.N., Hunyadi, D., de Lucena, A.L.A. et al. Thermal decomposition of ammonium molybdates. J Therm Anal Calorim 124, 1013–1021 (2016). https://doi.org/10.1007/s10973-015-5201-0

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10973-015-5201-0

Keywords

Search

Navigation