Green rusts and the corrosion of iron based materials J.-M. R. Génin et al. Institut Jean Barriol Laboratoire de Chimie Physique et Microbiologie pour

“Gütlich, Bill, Trautwein: Mössbauer Spectroscopy and Transition Metal Chemistry@Springer-Verlag 2009”

Green rusts and the corrosion of iron based materials

J.-M. R. Génin et al.

Institut Jean BarriolLaboratoire de Chimie Physique et Microbiologie pour l'Environnement, UMR 7564 CNRS-

Université Henri Poincaré-Nancy 1,Département Matériaux et Structures, ESSTIN,

405 rue de Vandoeuvre, F-54600 Villers-lès-Nancy, France. E-Mail:[email protected]

“Gütlich, Bill, Trautwein: M össbauer Spectroscopy and Transition Metal Chemistry@�� Springer-Verlag 2009”


Green rusts, i.e. FeII-III hydroxysalts, are layered double hydroxides (LDH) constituted of [FeII

(1-x) FeIIIx (OH)2 ] x+ layers and

[(x/n)An-(mx/n)H2O]x-interlayers. Anions can be Cl-, CO3

2-, SO42-, HCOO-, C2O4

2-,, SeO42- …

For Chloride [FeII2FeIII(OH)6]+[Cl-2H2O]-

Sulphate [FeII4FeIII

2(OH)12]2+[SO42-8H2O]2-

Carbonate [FeII4FeIII

2(OH)12]2+[CO32-3H2O]2-

Two types of stacking by XRD: GR1 [R(-3)m] and GR2 [P(-3)m1]XRD pattern of hydroxycarbonate GR1(CO3

2-). (thesis of Omar Benali 2002).

R-3mXRD pattern of hydroxysulphate GR2(SO4

2-) (thesis of Rabha Aïssa 2004).

P-3m1


GR1(Cl-) GR1(CO32-) GR1(CO3

2-) GR2(SO42-)

x 0.33 0.25 0.33 0.33

RA RA RA RA

mm s-1 % mm s-1 % mm s-1 % mm s-1 %

D1 1.27 2.89 37 1.28 2.97 62 1.27 2.93 51 1.27 2.88 66

D2 1.25 2.60 32 1.28 2.55 12 1.28 2.64 15

D3 0.47 0.41 31 0.47 0.43 26 0.47 0.42 34 0.47 0.44 34

Transmittance %

-4 -3 -2 -1 0 1 2 3 4

D3

D1

D2

78 K

Velocity (mm s-1)

94

95

96

97

98

99

100

Transmittance %

(c)

GR1(CO32-)

x = 0.33

D1

D3

D2

Velocity (mm s-1)-4 -3 -2 -1 0 1 2 3 482

87

92

97

Transmittance %

GR1(CO32-)

x = 0.25

78 K

(b)

D3

D1

GR2(SO42-)

x = 0.33Transmittance (%)

Velocity (mm s-1)-4 -3 -2 -1 0 1 2 3 4

78 K

(d)

88

90

92

94

96

98

100

100

98

96

92

94

-6 -4 -2 0 2 4 6

GR1(Cl-)x 0.33

78 K

(a)

Velocity (mm s-1)-4 -3 -2 -1 0 1 2 3 4

D2

D3D1Transmission

Mössbauer spectra measured at 78 K of various Green Rusts

2 ferrous doublets D1 & D2 (large )1 ferric doublet D3 (small )

x = FeIII / Fetotal is obtained directly from the spectrum (RA of D3)

Experimentally

0.25 < x < 0.33


S1

S2

after tf

-15 -10 -5 0 5 10 1592

94

96

98

100

Transmittance (%)

V (mm s-1)-15 -10 -5 0 5 10 15

92

94

96

98

100

D3

D2

D1

Transmittance (%)

V (mm s-1)15

t1

Most of the time the corrosion of iron ends into a ferric oxyhydroxide FeOOH

that is the result of the oxidation of the green rust by dissolution-precipitation

V (mm s-1)

-15 -10 -5 0 5 1092

94

96

98

100S2S1

D3

D1

Transmittance (%)

V (mm s-1)

t2

-15 -10 -5 0 5 10

85

90

95

100

D2

D3

D1

Transmittance (%)

V (mm s-1)

tg

-15 -10 -5 0 5 10 1590

92

94

96

98

100

102

Transmittance (%)

15

t3

D4S1

S3

S2

pH

Eh

-0.6

-0.4

-0.2

0.0

0.2

0.4

t2

pH

Eh

t3

t1

tg

time (mn)0 100 200 300 400

0

2

4

6

8

tf(a)

D1, D2, D3 : GR1(CO32-)

doubletsS1 : ferrihydrite sextetS2, S3 : goethite sextetsD4 : ferrihydrite doublet

tg : GR1(CO32-) alone

t1 : GR1(CO32-) + some

ferrihydrite

t2 : GR1(CO32-) + goethite +

ferrihydrite

t3 : goethite + ferrihydrite

After tf : goethite alone

Carbonate containing medium

Eh and pH monitoring of the solution with time

Mössbauer spectra during the oxidation by dissolution-

precipitation

(O. Benali)


H2O2

Quadrupole splitting (mm s-1)

x = 1

84

88

92

96

100

x = 1

78 K(e)

94

96

98

100

Transmittance %

Velocity (mm s-1)-4 0 4-2 2-4 -3 -2 -1 0 1 2 3 4

Velocity (mm s-1)

x ~ 0.78

78 K (d)

Transmittance %

D3D1

D2

78 K

-4 -3 -2 -1 0 1 2 3 4Velocity (mm s-1)

99

94

95

96

97

98

100

Transmittance %

(a)

x = 0.33


x ~ 0.50

D3

33 %D4

16.5 %78 K

Probability density (p) (b)

-1 0 1 2 3

D1

38 %

D2

12.5 %

x = 0.33 D3

33 %

78 K

Probability density (p)

(a)

-1 0 1 2 3

D1

50 %

D2

17 %


84

88

92

96

100

Transmittance %

(b)

x ~ 0.50

78 K

-4 -3 -2 -1 0 1 2 3 4Velocity (mm s-1)


D3

32 %

D4

31 %

78 K


(c)

-1 0 1 2 3

D1

28 %

D2

9 %

x ~ 0.63

(c)

x ~ 0.63

84

88

92

96

100

Transmittance %

78 K

-4 -3 -2 -1 0 1 2 3 4Velocity (mm s-1)

0.2 0.4 0.6 0.8 1.0 1.2 1.4

-0.2

-0.1

0.0

0.1

0.2

0.3

Eh(V)

{2 × [n(H2O2) / n(Fetotal)] + (1/3)}


D3

35 %

D4

43 %

78 K

Probability density (p) (d)

-1 0 1 2 3

D1 + D2

22 %

x ~ 0.78

D3

33 %

D4

67 %

78 K

(e)

-1 0 1 2 3


with H2O2

a

bc

de

FeII6(1-x) FeIII

6x O12 H2(7-3x) CO3

The in situ oxidation of green rusts by deprotonationUse a strong oxidant such as H2O2, Dry the green rust and oxide in the air,

Violent air oxidation, Oxide in a basic medium…

FeII-III oxyhydroxycarbonate0 < x < 1

“Gütlich, Bill, Trautwein: M össbauer Spectroscopy and Transition Metal Chemistry@�� Springer-Verlag 2009”


003

0.2 µm

(a)GR(CO3

2-)

x = 0.33

0.2 µm

(b)H2O2

x = 0.50(c)

0.5 µm

H2O2

x = 1

(d)

0.5 µm

Aerialx = 1

10 20 30 40

Intensity (arb. unit)

Diffraction Angle (2

(c)

113

110018

012

015006

(a) (b)

(d)

10 20 30 40

Intensity (arb. unit)

Diffraction Angle (2TEM and XRD patterns of the FeII-III oxyhydroxycarbonate due to the in situ deprotonation


G

G

G

2 (°)

(b) K(Mo G

G

G

-12 -8 -4 0 4 8 12Velocity (mm s-1)

293 KGR*

-12 -8 -4 0 4 8 12Velocity (mm s-1)

293 KGoethite (G)-FeOOH

0 10 20 30 400 10 20 30 40 50

K(Mo

00.3GR*

00.6GR*

01.2GR*

01.8GR*

(c)

01.5GR*

2 (°)

Intensity (u. a.) (a)

G

M

GM

M

MM

M

G

0 10 20 30 402 (°)

-12 -8 -4 0 4 8 12Velocity (mm s-1)

293 KMagnetite (M) + Goethite (G)

tf

x(O2) = 20% (750 rpm)

20% …13,3%...6,7% ………. 2,7% (375 rpm)E

C

B

4000 800 1200200 600 1000

M + G

GG

-400

-200

0

200

400GGR1(CO3

2-)*

Reaction time (min)tg

Eh (mV)

(c) (a)(b)

End products of oxidation

(A.Renard)

Oxidation by oxygen(a) & (b) Dissolution-

precipitation(1) FeII

4FeIII2(OH)12 CO3 + 3/4 O2 →

5 FeIIIOOH + CO32- + Fe2+ + 7/2 H2O

(2) 3Fe2+ + (1/4)O2 + (3/2) H2O -FeIIIOOH + 2 Fe3+ + H2

(3) FeII4FeIII

2(OH)12 CO3 + 1/3 O2 →5/3 FeIIFeIII

2 O4 + CO32- + Fe2+ + 6 H2O

(c) In situ deprotonation (4) FeII

4FeIII2(OH)12CO3 + O2 →

FeIII6O12H8CO3 + 2 H2O

Both modes of oxidation exist depending on the rate of oxygen

B

C

D

C

D


D1 +D2

D3

CEMS spectrum at room temperature of a steel disk dipped 24 hours in a 0.1 M NaHCO3 solution.

-Fe

Dissolution and

Precipitation

CORROSION

In situ deprotonation of GR1(CO3

2-)

PASSIVATION

pH

-FeOOH

H2CO3

HCO3-

CO32-

Fe++

FeOH+ FeOOH-

Fe(OH)2Fe

5 6 7 8 9 10 11 12 13 14

Eh(V)0.4

-0.2

0

0.2

-0.8

-0.4

-0.6

Fe(OH)2+

GR(CO32-)

The first step of corrosion:the green rust layer

[Fe2+] is 10-6 M

Eh-pH Pourbaix diagrams of GR(CO3

2-)

Aqueous corrosion of ironIron, Steels

Ferrous hydroxide

Agressive anions (Cl-, CO32-, SO4

2-)

Green rusts

Common rusts Ferric green rusts

including anions

Fe0

FeII

FeII-III

FeIII

Dissolution-precipitation In situ deprotonation

Goethite, Magnetite, Lepidocrocite, Akaganeite, -FeOOH, Ferroxyhite


20 µm

(e)

(A. Zegeye)

(G. Ona-Nguema)

(a) (b)

5 µm

(d)

(a) Production of Fe(II) and consumption of methanoate during culture of Shewanella putrefaciens in presence of lepidocrocite FeOOH. The initial amount of FeIII (as lepidocrocite ) and of methanoate were respectively 80 mM and 43 Mm.

(b) X-ray pattern of the solid phase of incubation experiments with S. putrefaciens: mixture of green rust (GR1) and siderite (S) obtained after 15 days of incubation.

(c) Mössbauer spectrum after 6 days of bioreduction.

(c) TEM observations and(d) optical micrograph of GR

crystals obtained by reduction of lepidocrocite by S. putrefaciens; One sees the bacteria that respirate GR*.

0

3

6

9

12

10 20 30 40 50 60

Intensity (a.u.)

2

GR1 (012)

GR1 (015)

GR1 (018)

GR1 (003)

GR1 (006)

S (104)

S (018)

Time (days)

0

10

20

30

40

50

60

70

0 6 12 18 24 30 36

Fe(II)Methanoate Abiotic control Methanoate (mM)

Fe(II) (mM)

80

GR* is also obtained by bacterial reduction

x ~ 0.50

(c)

Six days

Velocity (mm s-1)

Transmittance (%)

-4 -2 0 2 4

92

94

96

98

100D2

D

D’3D1

78 K

bioreduction


(a) SEM micrograph showing hexagonal shaped crystals of GR(SO42−) upon corroded steel sheet left 25 years in seawater,

(b) sequence of the rust layers: metal–magnetite–lepidocrocite–GR(SO42−), (c) Raman spectrum of the outer part of the marine

corroded layer.

(A. Zegeye)

Marine corrosion of steel and Microbially influenced corrosion

Formation of GR2(SO42-) during the reduction of -FeOOH by a

dissimilatory iron-respiring bacterium, Shewanella putrefaciens. Reduction was performed in a non-buffered medium without any organic compounds,

-4 -2 0 2 492

94

96

98

100

77 K

Transmittance (%)

Velocity (mm s-1)

D3

D2

D1D

Global computed

GR: Fe(II) = D1

GR: Fe(III) = D3

GR: Fe(II) = D2

Lepidocrocite = D

Experimental

Fe0

-FeOOH

GR(SO42-)

FeIIS

DIRB

SRB

GR(SO42-)

FeII

Microbially induced corrosion in marine sediments is due to the reduction of oxyhydroxides by dissimilatory iron reducing bacteria that respirates FeIII producing FeII-III oxyhydroxysulphate followed by its reduction into sulfides in acidic conditions due to sulphate reducing bacteria.

Mössbauer spectroscopy allowed us to study the family of FeII-III hydroxysalts known as green rusts, which are intermediate compounds during the corrosion of iron-based materials.There exist two modes of oxidation of the green rusts, either by dissolution-precipitation that leads to corrosion, or by in situ deprotonation giving rise to a ferric oxyhydroxysalt, e.g. FeIII6O12H8CO3, that leads to passivation of steels.

(c)

(Refait, Génin)

Documents

Green rusts and the corrosion of iron based materials J.-M. R. Génin et al. Institut Jean Barriol Laboratoire de Chimie Physique et Microbiologie pour