nanomaterials for catalysts - nanotechnology.de filethe 1st of december 2005 nanosciences and...

The 1st of December 2005 Nanosciences and Nanotechnology 1

Nanomaterials for catalystsNanomaterials for catalysts: : design and improvementdesign and improvement

PeterPeter Strizhak Strizhak andand Vyacheslav KhavrusVyacheslav Khavrus

L.V.L.V.Pisarzhevsky Institute Pisarzhevsky Institute of of Physical Physical Chemistry NationalChemistry National AcademyAcademy ofof

SciencesSciences of of UkraineUkraine• Introduction• The theory• Experiment• Conclusions


Our teamOur team


Kiev Kiev -- our cityour city


Practical application of nanomaterials in industry is a question of the nearest future. And only one branch of industry - heterogeneous catalysis -actively exploits nanomaterials during more than 20 years.

“Nanomaterials: Synthesis, Properties and Applications. 1996”


NanomaterialsNanomaterials

nanoparticlesnanoparticlesnanoporous materialsnanoporous materials

Nanotechnologies allow to obtain nanomaterials with a given nanoparticles (pores) size


ACTIVITY: ACTIVITY: macroscopic approachmacroscopic approach

Act

ivity

Size

→→Smooth dependencesSmooth dependences←←


QuantumQuantum--chemicalchemical approachapproach

0 2 4 6 8 10 12 14-119.8

-119.6

-119.4

-119.2

-119.0

-118.8

Ene

rgy

Number of Pt a toms0 1 2 3 4 5 6 7 8 9 10

0

1

2

3

4

5

6

7

Ene

rgy

Number of Pt a toms

→→Not smooth dependencesNot smooth dependences, , likelike jumpsjumps←←


The theory gives:

- macroscopic approachsmooth dependence of activity on size

- quantum-chemical approachnot smooth, like jumps dependence of activity on size


EXPERIMENT


CO oxidationnanoparticles:- ZnO/MgO- ZrO2- Fe3O4/Al2O3- Cr2O3/Al2O3- CuO/SnO2


CO oxidation on ZnO/MgO

6 7 8 9 10 110

5

10

15

20

TOF ⋅ 1

03 , s-1

dZnO , nm


CO oxidation on ZrO2

4 5 6 7 8 9 10 11 12 130

1

2

3

4

5

6

7

8

TOF ⋅ 1

06 , s-1

dZrO2, nm


CO oxidation on CuO/SnO2

6 8 10 12 14 16 18 200

20

40

60

80

TOF ⋅ 1

06 , s-1

dSnO2 , nm


CO oxidation on Fe3O4/Al2O3 and Cr2O3/Al2O3

8 12 16 20 24 28 32 36 40 44 480

1

2

3

4

5

6

7

8

TOF ⋅ 1

04 , s-1

dFe3O4, nm

5 10 15 20 25 30 35 40 450

2

4

6

8

10

TOF ⋅ 1

04 , s-1

dCr2O3, nm


PROX PROX -- preferential CO oxidationpreferential CO oxidation((coppercopper containingcontaining nanosizednanosized ZrZrOO22))

→→High conversion at low temperaturesHigh conversion at low temperatures←←


Hydrogenation of Hydrogenation of CO CO and organic nitrilesand organic nitriles

Hydrogenation of nitriles Hydrogenation of CO

0 20 40 60 80d, nm

-17

-16

-15

-14

-13

-12

ln r

1

2

3

4

5 6

7

8

0 40 80 120d, nm

-15

-14

-13

-12

-11

-10

ln r

Ni/Al2O3

Ni/MgO

Ni/SiO2Ni/Cr2O3

Ni/BeO

Ni/ZrO2

Ni/TiO2


OH O

CYCLOHEXANOLE DEHYDROGENATION

- Н2

Objects: industrial ZrO2 supported copper catalysts with various composition of metal


Comparison of various catalysts for cyclohexanol dehydrogenation

75

80

85

90

95

100

Cyclohexanoneproduction (%)

Cyclohexanoneselectivity (%)

Cu/ZrO2 NTK-4 NTK-10FM

→→High selectivityHigh selectivity←←


Methane partial oxidation to formaldehydeMethane partial oxidation to formaldehyde

OHOCHOCH OV22

support/24

52 +⎯⎯⎯⎯ →⎯+


Effect of pore size on selectivityEffect of pore size on selectivity

2 3 4 5 6 7 80

5

10

15

20

Sele

ctiv

ity, %

dpore , nm


ACIDACID--BASE CATALYSISBASE CATALYSIS


Toluene chain alkylation by methanol on Cs-containing

zeolites


0

10

20

30

40

50

60

70

0,5-0,6 nm(MTW: ZSM-11,

ZSM-12)

0,6-0,7 nm(*BEA, BOG,LTL, VPI-8)

0,74 nm (FAU)

Effect of pores size in zeolites

Size of zeolite pores, nm

Tot

alco

nver

sion

, pro

duct

ivity

an

d se

lect

ivity

on

ethy

lben

zene

an

d st

yrol

(%)

SelectivityEB+St

Cavities1,2 nm

Conversion ProductivityEB+St


ETBE synthesis from ethanol and ETBE synthesis from ethanol and isobuthyleneisobuthylene

Zeolite H-β (SiO2/Al2O3= 40 – 800)

Zeolite H-ZSM-5 (SiO2/Al2O3 = 40 – 800)

SulphocationiteAmberlyst 15

Modified silica (SiO2-SO3H) Mesoporous sieves and synthetic activated coal


Effect of pore size on activity Effect of pore size on activity in synthesisin synthesis ofof ETBEETBE

0 10 20 30 400

1

2

3

4

dpore , nm

r ETB

E , m

l/g/h

our


Carbon nanotube synthesis

1. CO+H2+Ar, Mo-Co-Ni/γ-Al2O3, T=750 oC

2. C2H4+H2+Ar+ H2O (vapor), Co or Ni nanoparticles, T=750 oC

3. C2H5OH(vapor)+H2+Ar, Co or Ni nanoparticles, T=750 oC


Carbon nanotube synthesis

Raman spectra analysisCC2H4, vol.% Intensity - Me Intensity - Other Me/Other

5.7 13243 6777 1.957.0 5136 3047 1.698.0 4329 2681 1.619.1 9895 4878 2.039.9 17558 8334 2.11


Nanomaterials for the catalyst: design and improvement

CONCLUSIONSCONCLUSIONS

•low temperature CO oxidation •PROX (preferential CO oxidation)•cyclohehanole dehydrogenation•acid-base catalysis•methane partial oxidation to formaldehyde•CO hydrogenation•hydrogenation of nitriles•CNT synthesis


ThankThank youyou!!

nanomaterials for catalysts - nanotechnology.de filethe 1st of december 2005 nanosciences and...

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