Catalysis Intro

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Introduction to Catalysis

Department of Chemical Engineer ing I I T Madras

R. Vinu

4th Feb. 2015 1


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Modak, J. M. Chemical Reaction Engineering Course Lectures, 2005, Indian Institute of Science, Bangalore

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Potential Energy Surface (PES) of catalytic and

non-catalytic reaction

Schmidt, L. D. The engineering of chemical reactions, Oxford University Press, 2005, New York

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Energy diagram for CO oxidation on Pt catalyst

All energies in kJ/mol

Non-catalytic route

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Transition

state

Davis, M. E.; Davis, R. J. Fundamentals of Chemical Reaction Engineering, McGraw Hill, 2003


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Some commercial processes and the

catalysts used


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Schmidt, L. D. The engineering of chemical reactions, Oxford University Press, 2005, New York


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Terms you should know

Homogeneous vs heterogeneous catalysis

Active Site, Support

Turnover frequency/number


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The Monsanto Process

Homogeneous catalytic cycle - example

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Homogeneous catalytic cycle - example

Photocatalytic water gasshift reaction

Ziessel, R. Angew. Chem. Int. Ed. 1991, 30, 844-847.

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Heterogeneous catalysts

Modak, J. M. Chemical Reaction Engineering Course Lectures, 2005, Indian Institute of Science, Bangalore10


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NH3-O and NH3-OH activation on Pt(100) surface

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Van Santen R. A. Molecular Catalytic Kinetics Concepts, Wiley-VCH, 2010


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Direct NH3 activation vs NH3 activation withadsorbed O on Pt(111)

E

n e r g y i n k J / m o

l

Van Santen R. A. Molecular Catal tic Kinetics Conce ts, Wile -VCH, 2010


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Multiscale Outlook

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Key Steps

Modak, J. M. Chemical Reaction Engineering Course Lectures, 2005, Indian Institute of Science, Bangalore

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Types of heterogeneous catalysts


Monoliths

Fu-Zhen, Z.; Guang-Hong, Z.; Peng-Hui, Z.; Xiao, Y.; Sheng-Fu, J. Chin. J. Catal. 2011, 32, 821-826.

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Wire Gauze

Wires made of Pt or Pt-RhE.g. High temp. oxidation of ammonia and hydrocarbons

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D t t f Ch i l E i i I I T M d


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Correlation between pore size of molecular sieves anddiameter of various molecules

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D a v i s , M . E . ; D a v i s , R . J . F u n d a m

e n t a l s o f C h e m i c a l R e a c t i o

n E n g i n e e r i n g , M c G r a w H

i l l , 2 0 0 3



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Pore size distribution of zeolite compared to amorphoussilica

19Davis, M. E.; Davis, R. J. Fundamentals of Chemical Reaction Engineering, McGraw Hill, 2003



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Pore size… Not too large… Not too small… But just exact…

h t t p : / / t r a i n i n g . f c p s . o r g / t t 6 / K i n d e r g a r t e n / t e d d y b / P r e s c h o o l % 2 0 P r i n t a b l e s %

2 0 - % 2 0 A c t i v i t y % 2 0 P a g e % 2 0 - % 2 0 F a i r y % 2 0 T a l e s % 2 0 -

% 2 0 G o l d i l o c k s % 2 0 a n d % 2 0 T h e % 2 0 T h r e e % 2 0 B e a r s % 2 0 S i z i n g % 2 0 ( c )_ f i l e s / 3 b e a r s_

s i z i n g c . g i f , a c c e s s o n 7 t h F e b . 2 0 1 3

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http://www.google.co.in/url?sa=i&rct=j&q=goldilocks+and+the+three+bears&source=images&cd=&cad=rja&docid=P4OlaDZ4O2yW_M&tbnid=-K7UlxDYq-qWCM:&ved=0CAUQjRw&url=http://training.fcps.org/tt6/Kindergarten/teddyb/Preschool%20Printables%20-%20Activity%20Page%20-%20Fairy%20Tales%20-%20Goldilocks%20and%20The%20Three%20Bears%20Sizing%20(c).htm&ei=qzITUYD5FseXiAe48oCICw&psig=AFQjCNHfJRTPnuN021HUy_sR268oFJiSPw&ust=1360299038799334http://www.google.co.in/url?sa=i&rct=j&q=goldilocks+and+the+three+bears&source=images&cd=&cad=rja&docid=P4OlaDZ4O2yW_M&tbnid=-K7UlxDYq-qWCM:&ved=0CAUQjRw&url=http://training.fcps.org/tt6/Kindergarten/teddyb/Preschool%20Printables%20-%20Activity%20Page%20-%20Fairy%20Tales%20-%20Goldilocks%20and%20The%20Three%20Bears%20Sizing%20(c).htm&ei=qzITUYD5FseXiAe48oCICw&psig=AFQjCNHfJRTPnuN021HUy_sR268oFJiSPw&ust=1360299038799334


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Volcano plot for the decomposition of formic acid on transition metals

Sabatier Principle


http://en.wikipedia.org/wiki/File:Volcano_plot.png, accessed on 7th Feb. 201321

Heat of formation of metal formate

T e m

p e r a t u r e c o r r e s p o n

d i n g t o a s p e c i f i c r a t e

The interactionbetween asubstrate and acatalyst should be just right


http://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.pnghttp://en.wikipedia.org/wiki/File:Volcano_plot.png


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Ce4+

Pd2+

O2-

Oxide ion

Vacancy


Doped vs Impregnated catalysts

1 at.% Pd-doped-CeO2

200 nm

Ag clusters

on TiO2

1 at.% Ag-impregnated-TiO2



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Characterization of a catalyst pellet/particle

What are the various measures/methods?


Single crystal / powder XRD

X ray PhotoelectronSpectroscopy (XPS)

FT-IR/Raman

Nuclear Magnetic Resonance

Electron microscopy

X ray Fluorescence (XFS)

Temperature programmeddesorption (TPD)

Ultraviolet Spectroscopy

Photoluminescence

Porosimetry (BET, BJH)

Thermogravimetric analysis

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Pre-exponential factors for selected unimolecular surfacereactions

2Hads→ H2,g on transitionmetal surfaces

24Davis, M. E.; Davis, R. J. Fundamentals of Chemical Reaction Engineering, McGraw Hill, 2003



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Measures of reaction rates

25Levenspiel, O. Chemical Reaction Engineering, 3rd Ed. John Wiley and Sons, Singapore.



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Catalytic batch reactor configurations

26Levenspiel, O. Chemical Reaction Engineering, 3rd Ed. John Wileyand Sons, Singapore.



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Cranberry – basket type CSTR




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Circulating fluidized bed reactor




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Concentration and temperature profiles

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Who are the key players/top catalyst companies?


Haldor Topsoe – Denmark

UOP – USA

Axens – France

Johnson Matthey – UK CRI/Criterion – Shell – USA

Süd-Chemie – Germany

Albemarle – USA

Grace Davison – UK

BASF – Germany

Exxon Mobil - USA

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What next?

Surfacereactionkinetics

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Catalysis Intro

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