Abstract
In this work, manganese and copper promoter effect was investigated over iron oxide obtained by thermal decomposition of iron(III) hydroxoacetate (nominal ratio Fe/Mn = 10 and Fe/Cu = 10). The solids were characterized by X-ray fluorescence, thermal analysis (TG, DTG, DTA), Fourier transform infrared spectroscopy (FTIR), physisorption experiments, thermoprogrammed reduction and powder X-ray diffraction. During the precursor thermal decomposition process, the step referred as dehydration/dehydroxylation was controlled by volatile species diffusion. Decomposition stage [Fe(III) to Fe(II) reduction] was controlled by solid geometry and particle size (Coats–Redfern model). FCA-C sample showed Fe(II)/Fe(III) the highest ratio, indicating that through precursor decomposition process reduction is favored. With the use of Ozawa and Kinssinger methods, it became clear that FMCA precursor decomposition showed the lowest activation energy value leading to solid FMCA-C with higher specific surface area and pore volume than the iron oxide-free dopants. The FMCA-C sample reduces hematite to magnetite (low temperature) easily and shows the highest stability of magnetite under reductive conditions.
References
Meshkani F, Rezaei M. Preparation of nanocrystalline metal (Cr, Al, Mn, Ce, Ni, Co and Cu) modified ferrite catalysts for the high temperature water gas shift reaction. Renew Energy. 2015;74:588–98.
Meshkani F, Rezaei M, Jafarbegloo M. Applying Taguchi robust design to the optimization of the synthesis parameters of nanocrystalline Cr-free Fe–Al–Cu catalyst for high temperature water gas shift reaction. Mater Res Bull. 2015;70:229–35.
Leea D, Leea MS, Leea JY, Kima S, Eoma H, Moonc DJ, Leea K. The review of Cr-free Fe-based catalysts for high-temperature water-gas shift reactions. Catal Today. 2013;210:2–9.
Fonseca JSL, Albuquerque RTV, Souza MOG. Catalytic properties of iron oxides impregnated with copper acetate. React Kinet Catal Lett. 2007;91:127–30.
Varela MCR, Filho MFJ, Galembeck F. Effect of acetate on ferrihydrite crystallization. Hyperfine Interact. 1994;83:161–7.
Liang X, Zhong Y, Tan W, Zhu J, Yuan P, He H, Jiang Z. The influence of substituting metals (Ti, V, Cr, Mn, Co and Ni) on the thermal stability of magnetite. J Therm Anal Calorim. 2013;111:1317–24.
Liang X, Zhong Y, Zhu S, He H, Yuan P, Zhu J, Jiang Z. The valence and site occupancy of substituting metals in magnetite spinel structure Fe3−xMxO4 (M = Cr, Mn, Co and Ni) and their influence on thermal stability: an XANES and TG-DSC investigation. Solid State Sci. 2013;15:115–22.
Muraleedharan K. Thermal decomposition kinetics of potassium iodate. J Therm Anal Calorim. 2013;114:491–6.
Vergara UL, et al. Polymerization and curing kinetics of furan resins under conventional and microwave heating. Thermochim Acta. 2014;581:92–9.
Koga N. Ozawa’s kinetic method for analyzing thermoanalytical curves. J Therm Anal Calorim. 2013;113:1527–41.
Keerthana DS, Namratha K, Byrappa K, Yathirajan HS. Facile one-step fabrication of magnetite particles under mild hydrothermal conditions. J Magn Magn Mater. 2015;378:551–7.
Mozaffari M, Amighian J, Tavakoli R. The effect of yttrium substitution on the magnetic properties of magnetite nanoparticles. J Magn Magn Mater. 2015;378:208–12.
Ding M, et al. Influence of manganese promoter on co-precipitated Fe–Cu based catalysts for higher alcohols synthesis. Fuel. 2013;109:21–7.
Jeong D, Subramanian V, Shim J, Jang W, Seo Y, Roh H, Gu JH, Lim YL. High-temperature water gas shift reaction over Fe/Al/Cu oxide based catalysts using simulated waste-derived synthesis gas. Catal Lett. 2013;143:438–44.
Meshkani F, Rezaei M. A highly active and stable chromium free iron based catalyst for H2 purification in high temperature water gas shift reaction. Int J Hydrog Energy. 2014;39:18302–11.
Acknowledgements
The authors wish to acknowledge the financial support received from Capes (Coordenação de Aperfeiçoamento de Pessoas de Nível Superior) and Dr. Maria do Carmo Rangel and Dr. Soraia Teixeira Brandão—Universidade Federal da Bahia (UFBA)—for analysis support.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
dos Santos Monteiro, D., da Guarda Souza, M.O. Thermal decomposition of precursors and iron oxide properties. J Therm Anal Calorim 123, 955–963 (2016). https://doi.org/10.1007/s10973-015-4840-5
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10973-015-4840-5