Determination of Fe2+/Fe3+ mole ratio based on the change of precursor lattice parameters of wustite based iron catalysts for the ammonia synthesis

Open access

Abstract

In the presented article, oxide forms of iron catalysts with the wustite structure and with a R = Fe2+/Fe3+ molar ratio in the range from 3.78 to 8.16 were investigated. The chemical composition of the tested catalyst precursors was determined by inductively coupled plasma optical emission spectrometry (ICP-OES). The X-ray diffraction (XRD) technique was used to determine the phase composition and location of reflections characteristic of the Fe1−xO phase. The molar ratio of iron ions R = Fe2+/Fe3+ was determined by manganometric titration. The distribution of promoters in the structure of iron catalyst precursors with different R = Fe2+/Fe3+ ratio was determined by a selective etching method. The dependence of the lattice parameter ao value in the crystal structure Fe1−xO on the molar ratio R = Fe2+/Fe3+ was determined. On the basis of the determined dependence, R can easily be calculated in catalyst precursors of the wustite structure.

If the inline PDF is not rendering correctly, you can download the PDF file here.

  • 1. Liu H.Z. Li X.N. & Hu Z.N. (1996). Development of novel low temperature and low pressure ammonia synthesis catalyst. Appl. Catal. A Gen. 142(2) 209–222. DOI: 10.1016/0926-860X(96)00047-6.

  • 2. Liu H. & Li X. (1997). Relationship between Precursor Phase Composition and Performance of Catalyst for Ammonia Synthesis. Ind. Eng. Chem. Res.. 36(2). 335–341. DOI: 10.1021/ie960072s.

  • 3. Liu H. (1986). China Patent no. 86108528.0.

  • 4. Zheng Y.F. Liu H.Z. Liu Z.J. & Li X.N. (2009). In situ X-ray diffraction study of reduction processes of Fe3O4– and Fe1−xO-based ammonia-synthesis catalysts. J. Solid State Chem. 182(9). 2385–2391. DOI: 10.1016/j.jssc.2009.06.030.

  • 5. Liu H. &Han W. (2017). Wüstite-based catalyst for ammonia synthesis: Structure property and performance. Catal. Today 297. 276–291. DOI: 10.1016/j.cattod.2017.04.062.

  • 6. Pernicone N. Ferrero F. Rossetti I. Forni L. Canton P. Riello P. Fagherazzi G. Signoretto M. & Pinna F. (2003). Wustite as a new precursor of industrial ammonia synthesis catalysts. Appl. Catal. A Gen. vol. 251(1). 121–129. DOI: 10.1016/S0926-860X(03)00313-2.

  • 7. Jedrzejewski R. & Lendzion-Bieluń Z. (2018). Reduction Process of Iron Catalyst recursors for Ammonia Synthesis Doped with Lithium Oxide. Catalysts. 8(11). 494. DOI: 10.3390/catal8110494.

  • 8. Lendzion-Bieluń Z. Jędrzejewski R. Ekiert E. & Arabczyk W. (2011). Heterogeneity of ingot of the fused iron catalyst for ammonia synthesis. Appl. Catal. A Gen. 400. 48–53. DOI: 10.1016/j.apcata.2011.04.010.

  • 9. Lendzion-Bieluń Z. & Arabczyk W. 2001. Method for determination of the chemical composition of phases of the iron catalyst precursor for ammonia synthesis. Appl. Catal. A Gen.. 207(1-2). 37–41. DOI: 10.1016/S0926-860X(00)00614-1.

  • 10. Arabczyk M.J.W. Ziebro J. Kałucki K. & Świerkowski R. (1996). Instalacja do ciągłego wytopu katalizatorów zelazowych. Chemik.1. 22–24.

  • 11. Lendzion-Bieluń Z. Arabczyk W. & Figurski M. The effect of the iron oxidation degree on distribution of promotors in the fused catalyst precursors and their activity in the ammonia synthesis reaction. Appl. Catal. A Gen. vol. 227(1-2). 255–263. DOI: 10.1016/S0926-860X(01)00938-3.

  • 12. Han W. Huang S. Cheng T. Tang H. Li Y. & Liu H. (2015). Promotion of Nb2O5 on the wustite-based iron catalyst for ammonia synthesis. Appl. Surf. Sci. 353. 17–23. DOI: 10.1016/j.apsusc.2015.06.049.

  • 13. Chaklader A.C.D. & Blair G.R. (1970) Differential thermal study of FeO and Fe3O4. J. Therm. Anal. 2(2). 165–179. DOI: 10.1007/BF01911348.

  • 14. Figurski M.J. Arabczyk W. Lendzion-Bieluń Z. Kaleńczuk R.J. & Lenart S.X. On the distribution of aluminium and magnesium oxides in wustite catalysts for ammonia synthesis. Appl. Catal. A Gen. 247(1). 9–15. DOI: 10.1016/S0926-860X(03)00084-X.

Search
Journal information
Impact Factor

IMPACT FACTOR 2018: 0.975
5-year IMPACT FACTOR: 0.878

CiteScore 2018: 1

SCImago Journal Rank (SJR) 2018: 0.269
Source Normalized Impact per Paper (SNIP) 2018: 0.46

Metrics
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 84 84 22
PDF Downloads 82 82 26