ingas 6-months meeting, prague, czech republic, 25-26 may 2009 ingas integrated gas powertrain 1...

INGAS INGAS 6-months Meeting6-months Meeting, , PraguePrague, , Czech Republic, 25-26 May 2009Czech Republic, 25-26 May 2009

INGAS INtegrated GAS PowertrainINGAS INtegrated GAS Powertrain

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Institute of Catalysis and Surface ChemistryPolish Academy of Sciences

6 months research activities

new catalyst formulations based on Cu-Mn mixed oxides

• synthesis

• physico-chemical characterization

• preliminary catalytic testing

WP2.2 Advanced Catalyst Development



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Synthetic approach for preparation of mixed oxide precursors:

• citrate method (sol-gel)

• hydrotalcite method




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Cu(II), Mn(II), Al(III) nitrates 2.5 M Citric acid

Viscous solution

Citrate Gel

Xerogel

Mixed oxide

Calcination 550oC

Drying 250oC

Stirring 65oC

Citrate method Hydrotalcite method

Cu(II), Mn(II), Al(III) nitrates

1 M Na2CO3/NaOH

Precipitation pH=9, 55oC

Hydrotalcite

Mixed oxide

Calcination 450oC

Drying 50oC



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Brucite Mg(OH)2

Hydrotalcite [(Mg0.75Al0.25)(OH)2](CO3)0.125·0.5H2O

[(Mg0.75Al0.25)(OH)2]0.25+

(CO3)2-

0.125

(H2O)0.5

Synthetic hydrotalcite [M2+

(1-x)M3+

x(OH)2]x+An-

x/nyH2O



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Synthetic hydrotalcite

[M2+(1-x)M

3+x(OH)2]

x+An-x/n

Synthetic hydrotalcite

M2+ = Mg, Ni, Zn, Fe, Co, Cu, Mn…

M3+ = Al, Mn, Fe, Cr ….

An - = CO32 –, NO3-, Cr2O7

2-, PMo12O403-…

0.20<x<0.33

[M2+(1-x)M

3+x](OH)2

[M2+(1-x)M

3+x](OH)2

[M2+(1-x)M

3+x](OH)2

An- An- An-

An- An- An-

An-An-An-An-

An-

[M2+(1-x)M

3+x](OH)2

An- H2O H2O

H2O H2O

H2O

H2O

H2O H2OH2O

Natural Hydrotalcite

M2+= Mg2+

M3+= Al3+

An-= CO32-, NO3

-

x = 0.25




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2 12 22 32 42 52 62 72

2 Theta CuKα

Inte

nsit

y [

a.u

.]

o - MnCO3

MnAlCO3 (2:1)

CuAlCO3 (2:1)

CuMnAlCO3 (2:1:1)

CuMnAlCO3 (1:1:1)

CuMnAlCO3 (1:2:1)

CuMnAlCO3 (4:4:1)

CuMnAlCO3 (12:5:1)

XRD of Cu-Mn-Al hydrotalcite-like precursors



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0

500

1000

1500

2000

2 12 22 32 42 52 622

RT

3000C

2000C

1000C

8000C

6000C

5000C

4000C

CuMn2O4

CuOHTlc CuAlCO3

Mn2AlO4MnAl2O4


Thermal decomposition of

CuMnAl/1:1:1/ hydrotalcite-like

precursor monitored in a high

temperature XRD chamber



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SampleOxidic phases after calcination at

373 K 473 K 573 K 673 K 773 K 873 K 973 K 1073 K 1173 K

CuAlCO3

(2:1)

HT HT --- --- CuO CuO CuOCu2Al4O7

CuOCu2Al4O7

CuOCu2Al4O7

CuMnAlCO3

(12:5:1)

HTR

R --- --- CuMn2O4

CuO

CuMn2O4

CuO

CuMn2O4

CuO

CuMn2O4

CuO

CuMn2O4

CuO

CuMnAlCO3

(4:4:1)

HTR

R --- --- CuMn2O4

CuO tracesMn2O3

traces

CuMn2O4

CuOMn2O3

Mn2AlO4

CuMn2O4

CuO

Mn2AlO4

CuMn2O4

CuO

CuMnO2

MnAl2O4

CuMnAlCO3

(2:1:1)

HT --- --- --- CuMn2O4 CuMn2O4

CuO traces

CuMn2O4

MnAl2O4

CuO

CuMn2O4

MnAl2O4

CuO

CuMn2O4

CuOMnAl2O4

CuMnAlCO3

(1:1:1)

HTR

R --- --- CuMn2O4 CuMn2O4

(weak)Mn1+xAl2-xO4

CuMn2O4

Mn2AlO4

MnAl2O4

CuMn2O4

CuOMn2AlO4

CuMn2O4

CuOMn2AlO4

CuMnAlCO3

(1:2:1)

HTR

R --- --- CuMn2O4 CuMn2O4

Mn2O3

CuMn2O4

Mn2O3

Mn2AlO4

CuMn2O4

Mn2O3

traces

Mn2AlO4

CuMn2O4

MnAlCO3

(2:1)

HTR

--- --- --- Mn3O4 Mn3O4 Mn3O4 Mn2AlO4

Mn2O3

Mn2AlO4




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XRD of mixed oxides derived from hydrotalcite-like precursors

2 12 22 32 42 52 62 722 Theta CuKα

Inte

nsit

y [

a.u

.]

CuO

CuMn2O4

Mn3O4

MnAl (2:1)

CuMnAl (2:1:1)

CuAl (2:1)

CuMnAl (4:4:1)

CuMnAl (1:2:1)

CuMnAl (1:1:1)

CuMnAl (12:5:1)




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Bulk vs. surface chemical composition

Sample Cu:Mn:Alatomic ratios-bulk values

(ICP OES)

Cu:Mn:Alatomic ratios

-surface values (XPS)

BET [m2/g]

CuMnAl (12:5:1) 13:5.1:1 4.7:2.1:1 55

CuMnAl (4:4:1) 4.1:4.2:1 0.9:1.6:1 61

CuMnAl (1:1:1) 1.1:1.2:1 1.2:1.8:1 96

CuMnAl (2:1:1) 2.1:1.1:1 1.2:0.6:1 62

CuMnAl (1:2:1) 1.1:2.2:1 0.9:1:1 132

MnAl (2:1) 2.3:1 0.4:1 237

CuAl (2:1) 2.2:1 0.2:1 30




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CuMnAl (1:1:1)

HAADF STEM shows that CuMnAl (1:1:1) is a mixture of semi-amorphous oxide phases of different composition. HRTEM proves that one of them is nanocrystalline spinel CuMn2O4.

HAADF STEM

Transmission Electron Microscopy

STEM of CuMnAl 6:2:15 nm

HRTEM




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CuAl (2:1) CuMnAl (2:1:1) CuMnAl (4:4:1)

precursor precursorprecursor

calcined calcined calcined

Scanning Electron Microscopy



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Cu 2p3/2,1/2 Mn 2p3/2,1/2 XPS

Sample % Cu+ % Cu2+ % Mn2+ % Mn4+

CuMn 1350C 5.1 42.65 31.5 68.5

CuMn 2400C 61.2 35.5 27.5 72.5

Contribution of various Cu and Mn oxidation states at the surface of a CuMnAl/2:1:1/Ht catalyst after exposure to air at different temperatures

reduction oxidation




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WP2.2 Advanced Catalyst Development H2 TPR of Cu-Mn-Al mixed oxides

derived from hydrotalcite precursors

300 500 700 900Temperature [K]

H2

co

ns

um

pti

on

[a

.u.] CuAl (2:1)

MnAl (2:1)

CuMnAl (2:1:1)

CuMnAl (12:5:1)

CuMnAl (1:1:1)

CuMnAl (4:4:1)

CuMnAl (1:2:1)

601 K

558 K

567 K

564 K

581 K

630 K

734 K

547 K



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XRD patterns of Cu-Mn-Al mixed oxides derived from citrate precursors.

0

100

200

300

400

500

600

700

800

900

1000

2,00 12,00 22,00 32,00 42,00 52,00 62,00 72,002 Theta

Cou

nts

MnAl/1:2/Cit

MnAl/2:1/Cit

CuMn/1:2/Cit

Cu1.5Mn1.5O4/CuMn2O4

Mn2O3



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MnAl/2:1/Ht MnAl/2:1/Cit

Influence of the nature of precursor

237 m2/g 77 m2/g



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CH4 combustionfixed-bed flow glass reactor, p=1 bar, temperature = 175-525oC, catalyst - 0.5 ml,

[CH4] = 1g/m3, GHSV = 10 000 h-1.

0

20

40

60

80

100

120

150 200 250 300 350 400 450 500 550

Temperature [oC]

CH

4 co

nve

rsio

n [

%]

.

ECOCAT REFERENCE

CuMnAl/4:4:1/Ht

CuMnAl/1:2:1/Ht

MnAl/2:1/Ht

CuAl/2:1/Ht

MnAl/1:2/Cit

CuMn/1:2/Cit

MnAl/2:1/Cit

Sample

T50

[oC]

BET [m2/g]

CuMnAl/4:4:1/Ht 389 61

CuMnAl/1:2:1/Ht 411 132

MnAl/2:1/Ht 412 237

CuAl/2:1/Ht 470 30

MnAl/2:1/Cit 478 77

MnAl/1:2/Cit 439 324

Cu/Mn/1:2/Cit 458 18

ECOCAT washcoat 255 n.d.



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Future action

• Further exploration along the compositions based on mixed Cu and Mn oxides, aiming at maximization of the specific surface area and simultaneous formation of the copper-rich spinel phase.

• Investigation of compositions enriched with promoters (e.g. Ce, Zr).

• Synthesis of perovskite and hexaaluminate precursors containing Co and La.

ingas 6-months meeting, prague, czech republic, 25-26 may 2009 ingas integrated gas powertrain 1...

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