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Concepts of Modern Catalysis and Kinetics. I. Chorkendorff, J.W. NiemantsverdrietCopyright © 2003 WILEY-VCH Verlag GmbH & Co. KGaA, WeinheimISBN: 3-527-30574-2

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Ib Chorkendorff and Hans Niemantsverdriet

Hans Ib


ammonia

synthesis

Langmuir

HinshelwoodIR

Surface

ScienceComputational

chemistryBerzelius

Equilibrium

Thermodynamics

1800 1900 2000

TST

Know

ledge

Heterogeneous CatalysisHow much do we know?

Prac

tical C

atalys

is

Unde

rsta

ndin

g


bondingreaction

separation

AB

catalyst

catalyst

catalyst

P

P

A B

Figure 1.1


bonding reaction separation

reaction coordinate

+

AB

catalyst

catalyst

A B

catalyst

Pcatalyst

P

A B P

po

ten

tia

l e

ne

rgy

Figure 1.2


bonding

reaction

separation

enzyme

substrate 1

substrate 2

product

Figure 1.3


+

adsorption reaction desorption

COO2

CO2

catalyst

adsorption reaction desorption

reaction coordinate

E

Figure 1.5


catalyticsurface

catalytically active particles on a support

shaped catalyst particles

catalyst bed in a reactor

1 nm

10 mm

1 µm

1 m

microscopic mesoscopic macroscopic

Figure 1.8


Ea

Ed

∆H = Ed - EaEner

gy

(a.u

.)

reaction coordinate or distance X-X

A2

A AA2#A2

Figure 2.2


Figure 2.4

Catalyst

Flow reactor

tube

Batch reactor

tank


Figure 2.5

0,0

0,2

0,4

0,6

0,8

1,0

0,0

0,2

0,4

0,6

0,8

1,0

0,0

0,2

0,4

0,6

0,8

1,0

0 1 2 3 4 5 6 7 8 9 10

k1t

k2 = 0.2 k1

k2 = k1

k2 = 10 k1

[R]

[R]

[R]

[P]

[P]

[P]

[I]

[I]

[I]

conce

ntr

ation


B

A

A

A

AB

B

A

A

A

A

B

BB

B

BB

B

B

B

random ordered

r = N k θAθB r < N k θAθB

Figure 2.8


Figure 2.9

r << N k θAθB


Figure 2.10

Pressure (bar)0 1 2 3 4 5 6 7 8 9 10

θ co

vera

ge

0.0

0.2

0.4

0.6

0.8

1.0

K=0.1 bar-1

K=1 bar-1

K=10 bar-1


Figure 2.11 & 2.12

Ka=1 at 600 K, ∆Ηa=-125kJ/molKb=1 at 600 K, ∆Hb=-125kJ/mol, Kab small,k=1 at 540 K, Ea=+50kJ/mol, and Pb=5

0.0 0.2 0.4 0.6 0.8 1.00.0

0.2

0.4

0.6

0.8

1.0θ

and

Nor

mal

ized

Rat

e

θa

θb

θ*

Rate

χa=Pa/(Pa+Pb)

0.0 0.2 0.4 0.6 0.8 1.0

Rea

ctio

n or

der a

ndR

educ

ed A

ctiv

atio

n en

ergy

-1.0-0.8-0.6-0.4-0.20.00.20.40.60.81.0

na

Eapp/|Ea+∆Ha+∆Hb|

nb

CO oxidation, KCO=1 at 650 K, ∆ΗCO=-135kJ/molKo2=1 at 630 K, ∆HO2

=-250kJ/mol, KCO2 small,

k=1 at 540 K, Ea=50kJ/mol, PO2=10*PCO, and PCO=1

100 200 300 400 500 600 700 800 9000.0

0.2

0.4

0.6

0.8

1.0

θ an

d N

orm

aliz

ed R

ate

θO

θCOθ*

CO2 Rate

Temperature (K)

100 200 300 400 500 600 700 800 900

Rea

ctio

n or

der a

ndR

educ

ed A

ctiv

atio

n en

ergy

-1.0-0.8-0.6-0.4-0.20.00.20.40.60.81.0

nO2

Eapp/|Ea+∆Hco+0.5∆Ho2|

nCO


Figure 3.1

∆E

reaction coordinate

E

+

+k

A B AB


Figure 3.9

Density

Ener

gy (k

J/m

ol)

0

10

20

30

40

50

Reaction Coordinate

∆E

∆H

vx > vmin

vx < vmin

T=300K

T=600K

T=1000K


Figure 3.11

reaction coordinate

E

R

P

R#

reaction coordinate

E

R

P

R#

Loose TST:q# >> q

Tight TST:q# << q

1013 < ν < 1017 s-1109 < ν < 1013 s-1

∆E ∆E

∆S# negative ∆S# positive

reaction coordinate

E

R

P

R#

reaction coordinate

E

R

P

R#

Loose TST:q# >> q

Tight TST:q# << q

1013 < ν < 1017 s-1109 < ν < 1013 s-1

∆E ∆E

∆S# negative ∆S# positive


Figure 3.12

C

O

C

O

C

O

C

O

C

O

CO-vibration FrustratedRotation x

FrustratedRotation y

FrustratedTranslation y

FrustratedTranslation x

C

O

Reaction coordinate

C

O

C

O

C

O

C

O

C

O

C

O

C

O

C

O

C

O

C

O

CO-vibration FrustratedRotation x

FrustratedRotation y

FrustratedTranslation y

FrustratedTranslation x

C

O

C

O

Reaction coordinate


Figure 3.14

Adsorbed Transition Desorbed Preexponentialstate state state factor

∼ 1015 s-1

∼ 1013 s-1

∼ 1014-16 s-1

∼ 1013 s-1

mobile

immobile

immobile

mobile


Figure 4.1

Particle on a flat support Single crystal surface

High surfa

ce-area su

pport


Figure 5.16

Roughness• features are wider than they are deep• only external surface area

Porosity• features are deeper than they are wide• internal and external surface area


Figure 5.19-21

P/P0

“Point B”

submonolayer

monolayer

multilayerV

VM

Type IIisotherm

V

P/P0

(all micropores filled)

Capillary condensation

Type Iisotherm

“Point B”

submonolayer

monolayer

poresfilled

V

P/P0

VM

Type IVisotherm


Figure 5.24

0 250 500 750 1000 1250

0 250 500 750 1000 1250

Temperature °C

Gibbsite Al(OH)3non-porouscontains alkali

BoehmiteAlOOHporous, 100-400 m2/gforms from Al(OH)3 by heating

BayeriteAl(OH)3synthetic, can be prepared alkali free

DiasporeAl(OH)3forms by steaming of all Al-(hydr)oxides at high p,T

smallparticles

smallparticles

χ-Al2O3

γ-Al2O3spinel with stacking faults50-300 m2/g; ca. 0.6 cm3/g

η-Al2O3spinel, manystacking faults

κ-Al2O3

δ-Al2O3ortho-rhombic

θ-Al2O3monoclinic

θ-Al2O3monoclinic

α-Al2O3

α-Al2O3corundum, hexagonally close-packednon-porous, 3-5 m2/g

support

catalyst & support

support


Figure 5.26


Figure 5.27


Figure 5.37

1/T

Eapp =∆Eactgas phase reaction

transport limitation outside particles

pore diffusionEapp =½ ∆Eact

ln(r

ate) preferred

regime foroperation


strong weak no bondingatomic molecular atomic orbital orbital orbital

anti bonding

large small overlap

bonding

Figure 6.8


Figure 6.9

….


Figure 6.10

Ener

gy

Density of states (DOS)Atom Metal

4 p

4 s

3 d


EF

Evac

sp-band

core level 1

core level 2

metal adsorbed atom free atom

Work function

Vacuum level

Fermi levelεa

ionizationenergy

Figure 6.11


k momentum

ε k Ene

rgy

εk = h2k2/8π2m

εk EnergyD

OS

Den

sity

of S

tate

s

n(εk) ~ εk εF

1/2

Figure 6.12


surfacemetal vacuum

+ -+ -+ -+ -+ -+ -

electronsionic cores

distance

den

sity +

-

dipole

Figure 6.13


ε k En

ergy

DOS Density of States

εF

T=500 K

T=10000 K

εvac

Φ

T=5000 K

n(εk) ~ (εk) 0.5

Figure 6.14


a

ε0

Core level

Figure 6.15


-G0/2=-π/a-1 0 1

ε(k)

0

1

2

3

4

G0/2=π/a

ε(k)=ε0−α-2βcos(ka)

k

Figure 6.16


EF

Evac

valenceband

conductionband

free electron metal transition metal insulator

sp-band sp-band

d-band

sp-band

band gap

conductionband

Figure 6.17


Energy (eV)0 10 20 30 40

Den

sity

of S

tate

s (ar

b. u

nits

)

εa = 12 eV

∆(ε) = ∆0

na(ε)

Figure 6.20


Energy (eV)0 10 20 30 40

Den

sity

of S

tate

s (ar

b. u

nits

)

εa = 12 eV

na(ε)

n(ε) ∝ √ε

Λ(ε)

y = ε - εa

∆(ε) sp-band

Figure 6.21


Energy (eV)0 10 20 30 40

Den

sity

of S

tate

s D

ensi

ty o

f Sta

tes

εa = 12 eV

∆(ε) sp-band

na(ε)bonding

n(ε) ∝ √ε

Λ(ε)

y = ε - εa

na(ε)antibonding

∆(ε) d-band

Λ(ε)

Figure 6.22


Evac

EF

Metal Adsorbate levels

Distance from surface

Figure 6.23


Evac

EF

adsorbate levels

distance from surface

sp-band

d-band

metal

Figure 6.24


Evac

EF

metal adsorbate levels

distance from surface

s s

σ*

σ

sp-band

d-band

Figure 6.25


EFEd Ed

Ed

π∗ π∗ π∗

Figure 6.33


Reaction coordinate (arb. units)

En

erg

y (

arb

. u

nit

s)

dissociative chemisorption

associativechemisorption

physisorption (exaggerated)

metal +2X

metal +X2

metal-X

metal-X2

Ea

Ed

Figure 6.34


NN NNN

0.25 ML

0.50 ML

0

0

10

0

10

3

10 kJ/mol

-3 kJ/mol

ωA-A = NN

ωA-A = NNN

C(2x2) (2x2) (1x1)

Figure 7.9


θA = 0.25 ML

θB = 0.25 ML

θA = 0.25 ML

θB = 0.50 ML

ωA-A = NN

ωB-B = NN

ωA-B = NN

0

0

0

5

5

5

-5

-5

5

5 kJ/mol

5 kJ/mol

-5 kJ/mol

Figure 7.10


300 400 500 600

Temperature (K)

CO/Rh(100)

θCO(ML)

0.77

0.70

0.68

0.62

0.59

0.47

0.43

0.330.250.170.110.08

0.04

200 300 400 500 600

Temperature (K)

0.05

θCO(ML)

0.110.12

0.170.20

0.24

0.06

θN=0.5 ML

N

CO

N

N

NN

N

N

N N

N

N

N

N

CO

CO

CO + c(2x2)-N/Rh(100)

Figure 7.11


200 400 600 800T (K)

SIMS

0.20 ML

N2

NO

TPD

200 400 600 800T (K)

N2

NO

0.37 ML

200 600 800T (K)

N2

NO0.60 ML

NO/Rh(100)

NO molecules NO molecules + O,N atoms

O and N atoms

“θNO ” “θNO ” “θNO ”

“θN ”“θN ”“θN ”

400

Figure 7.12


Monte-Carlo Simulation of NO on Rh(100)

200 400 600 800T (K)

SIMS

0.20 ML

N2

NO

TPD

200 400 600 800T (K)

N2

NO

0.37 ML

200 400 600 800T (K)

N2

NO0.60 ML

Experimental: TPD and SIMS of NO on Rh(100)

NO molecules NO molecules + O, N-atoms O and N-atoms

θNO

θN

200 400 600 800 10000.0

0.1

0.2

0.3

0.4

0.5

0.6

Cov

erag

e (M

L)

Temperature (K)200 400 600 800 1000

Temperature (K)200 400 600 800 1000

Temperature (K)

rate

(a.u

.) 0.20 ML 0.37 ML 0.60 ML

θO

θNO

θN

θO

θNO

θN

θO

rdiss(NO) rdiss(NO) rdiss(NO)

rdes(NO) rdes(NO)

rdes(N2) rdes(N2) rdes(N2)

“θNO ” “θNO ” “θNO ”

“θN ”“θN ”“θN ”

Con

cept

s of M

oder

n C

atal

ysis

and

Kin

etic

s. I.

Cho

rken

dorf

f, J.W

. Nie

man

tsve

rdrie

tC

opyr

ight

©20

03 W

ILEY

-VC

H V

erla

g G

mbH

& C

o. K

GaA

, Wei

nhei

mIS

BN

: 3-5

27-3

0574

-2

Figure 7.12 - extra


Temperature (K)400 600 800 1000 1200

∆G

(kJ/

mol

)

-150

-100

-50

0

50

100

150

200 CH4 + H2O <−> CO + 3H2

CO + H2O <−> CO2 + H2

CH4 <−> C + 2H2

CO + H2 <−> C + H2O

2CO <−> C + CO2

Figure 8.1


Figure 8.15

0.0

0.1

0.2

0.3

0.4

0.5

0.0

0.2

0.40.6

0.81.0

0.00.2

0.40.6

0.8Met

hano

l equ

ilibr

ium

mol

e fr

actio

n

H 2 mole

frac

tion i

nlet

CO mole fraction inlet


Figure 8.28

2H2

Purge

O2

2H2O

APt or Pt/Ru clusters

H+

H+

H+

H+

Pt clusters

Protron membrane

Nafion

Porous electrodes


Figure 8.30

Effic

ienc

y

Load

~3000rpm

Drop due to internalresistance

Conventionalengines

Fuel cell driven


Figure 9.1

atmosphericdistillation

crudeoil

gas

naphta

kerosene

gas oil

vacuum gas oil

atmosphericresidue

vacuumresidue

vacuumdistillation

LPG

gasoline

kerosene

diesel

low sulfurfuel oil

reforming

hydrotreating

hydrocracking

hydrotreating

residue conversion

fcc


Figure 9.2

thiophene di-methyl di-benzothiophene

pyrrole

indole

carbazole

pyridine

quinoline

acridine


Figure 9.3


Figure 9.5

SCo, Mo

S

trigonal prism

MoS2

CoMoS phase

Co9S8

MoS2top view

Co in Al2O3


Figure 9.6

“MoS2”

H2S

C2H4

C2H5SH


Figure 9.8

thiophenetetra hydrothiophene

butadiene1-butene

2-butenes

- H2S

H2

H2

?


Figure 9.9

7%1%4%6%7%

11%

15%

17%

32%

otherbutaneisomerate (RON=85)hydrocrackate straight run naphtha (68)

MTBE (116)

alkylate (95)

reformate (99)

fcc naphtha (93-95)


Figure 9.10

Riser reactor770 K

Separator

Products

Regenerator1000 K

CO2, CO, H2O,flue gas

Feed injection


Figure 9.12

deh

ydro

gen

ation -

hyd

rogen

atio

n

met

al c

atal

yzed

isomerizationacid catalyzed

bifunctionalcatalysis

in reforming onPt / Al2O3

-H2 +H2 -H2 +H2

-H2 +H2 -H2 +H2

-H2 +H2 -H2 +H2

-H2 +H2

H+ H+

H+


Figure 9.13

O

O

O

Al OH

Al OH

O

O

O

Al O

Al O

O

O

O

Al Cl

Al OH

Pt

Cl

ClCl

Cl O

O

O

Al O

Al O

Pt

Cl

Cl

γ-Al2O3hydroxylated,

acidic support

+ OH-

+2H++2Cl-+2H++4Cl-

+PtCl6-

+Cl-

Cl / γ-Al2O3higher acidity


Figure 9.17

O|M

O|M

O|M

O|M

O|M

O|M

O|M

O|M

O|M M

O|M

O|M

O|C

CO½ O2

CO2

Mars-Van KrevelenMechanism


Figure 10.1

λ- value

Em

issi

ons

and s

enso

r si

gnal

Operatingwindow

oxygen sensor(λ-sensor)

0.85 1.051.000.950.90 1.201.151.10

NOxwith catalyst

without catalyst

Hydrocarbonswithout catalyst

Hydrocarbonswith catalyst

COwithout

with catalyst


Figure 10.5


Figure 10.10

0

0.02

0.04

0.06

0.08

0.10

0 2 4 6 8 10time (min)

NO

xco

nce

ntr

atio

n (

%) lean combustion A/F=23.5 lean lean

richspikeA/F=10

1 s

richspikeA/F=10

1 s

inlet gas

outlet gas

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