Preparation and characterization of Mn (H2PO4)2.2H2O crystal inhibitor for ordinary mild steel corrosion in simulated cooling water using FTIR, XRD and electrochemical measurements

Mustapha Ezzaafrani, Abdelaziz Ennaciri, Mohamed Harcharras, Redouane Khaoulaf, Mouhssin Galai, Rachid Touir, Mohamed Ebn Touhami, M Rossi, Francesco Capitelli


Manganese dihydrogen orthophosphate dihydrate Mn (H2PO4)2.2H2O was synthesized by solution co-precipitation method and characterized through single crystal X-ray diffraction, FT-IR and Raman spectroscopy. It crystallizes within monoclinic P21/n space group, with unit cell parameters a = 5.3733(3) Å, b = 10.1700(7) Å, c = 7.3106(5) Å and β = 94.786(7) °: the least–square refinement converged to final agreement factors R1=0.0200 and wR2=0.0548 (I>2σ (Iobs)). The three-dimensional network of the structure is made up by the repetition down (101) plane of layers of Mn octahedra and P tetrahedra joint together via vertex sharing. Strong O-H…O hydrogen bonds interconnect the layers, concurring to fix the network; such interactions were also investigated, as well as the whole structure, by means of infrared and Raman spectroscopy. Last, the corrosion inhibition for ordinary mild steel in simulated cooling water was investigated by this compound using electrochemical measurements. The results showed that it acts as a corrosion inhibitor and their inhibition efficiencies depend to its concentration.


Chanaiporn Danvirutai, Banjong Boonchomb, Sujittra Youngme. Journal of Alloys and Compounds 457 (2008) 75–80.

Averbuch-Pouchot, M.T.;Durif, A.;Guitel, J.C.;Tordjman, I.;Laugt, M . Bulletin de la Societe Francaise de Mineralogie et de Cristallographie 96 (1973) 278-280.

Hinsch, T.R.. Neues Jahrbuch fuer Mineralogie. Monatshefte (Band=Jahr) (1985) 439-445.

Guse, W.;Klaska, K.H.;Saalfeld,-H.;Adiwidjaja, G., Neues Jahrbuch fuer Mineralogie. Monatshefte (Band=Jahr) (1985) 433-438.

P. Vasicˇı, B. Prelesnik, M. Cˇ uric´, R.-Herak, Z. Krist. 173 (1985) 193.

V. Koleva,-H. Effenberger. J. Solid State Chem. 180 (2007) 956-967.

B. Boonchom, C. Danvirutai. Ind. Eng. Chem. Res. 46,9071 (2007).

B. Boonchom, S, Youngme, T. Srithanratana, C. Danvirutai. J. Therm. Anal. Calor. 91, 511 (2008).

O. Lahodny-Ŝarc, L. Kaštelan, Corros. Sci., 16, (1976) 25–34.

G. M. Sheldrick, SADBAS, Absorption Correction Program. University of Gottingen, Germany (1996).

A. Altomare, M. C. Burla, M. Camalli, G. L. Cascarano,C. Giacovazzo, A. Guagliardi, A.G.G. Moliterni, G. Polidori, R. Spagna, J. Appl. Crystallogr. 32, 115–119 (1999).

G. M. Sheldrick, SHELXL-97: Program for Crystal Structure Refinement, University of Gottingen, Germany (1997).

Chiari, G.; & Ferraris, G.: The water molecule in crystalline-Hydrates studied by neutron diffraction. Acta Cryst. B38 (1982) 2331-2341.

R. Touir, M. Cenoui, M. El Bakri, M. Ebn Touhami, Corros. Sci., 50 (2008) 1530–1537.

R. Touir, N. Dkhireche, M. Ebn Touhami, M. Lakhrissi, B. Lakhrissi, M. Sfaira, Desalination, 249 (2009) 922–928.

M. Cenoui, N. Dkhireche, O. Kassou, M. Ebn Touhami, R. Touir, A. Dermaj, N.-Hajjaji, J. Mater. Environ. Sci., 1 (2) (2010) 84-95.

N. Dkhireche, R. Abdelhadi, M. Ebn Touhami,-H. Oudda, R. Touir, M. Elbakri, M. 6R. Sfaira, B.-Hammouti, O. Senhaji, R. Taouil, Int. J. Electrochem. Sci., 7 (2012) 5314 - 5330.

S. Ramesh, S. Rajeswari, Electrochim. Acta, 49 (2004) 811-820.

M. Saremi, C. Dehghanian, M. Mohammadi Sabet, Corr. Sci., 48 (2006) 1404–1412.

M. Stern, A.L. Geary, J. Electrochem. Soc. 104 (1957) 56-63

A. Bouckamp, Users Manual Equivalent Circuit, Ver. 4.51, 1993.

Koleva, V., Stefov, V., Cahil, A., Najdoski, M., Å optrajanov, B., Engelen, B., Lutz, H.D.. Journal of Molecular Structure 917 (2009a) 117-124.

Koleva, V., Stefov, V., Cahil, A., Najdoski, M., Å optrajanov, B., Engelen, B., Lutz, H.D.. Journal of Molecular Structure 919 (2009b) 164-169.

K. NAKAMOTO, Infra-Red Spectra of Inorganic and Co-ordination Compounds, p. 156. Johtl Wiley (1963).

M. Pourbaix, Atlas of Electrochemical Equilibria in Aqueous Solutions, NACE,-Houston, (1974).

H. J. Flitt, D. P. Schweinsberg, Corros. Sci., 47 (2005) 3034–3052

A. Majjane, D. Rair, A. Chahine, M. Et-tabirou, M. Ebn Touhami, R. Touir, Corros. Sci., 60 (2012) 98–103.

Full Text: PDF


  • There are currently no refbacks.

Bookmark and Share

Creative Commons License
This work is licensed under a Creative Commons Attribution 3.0 License.