Geochemical Processes at Mineral Surfaces - American Chemical

samples were equilibrated for 24-72 h after preparation. The tem .... mol - 1 dm 3 s " 1 s " 1. -pKint. Ti0 2 / H +. 6.2 x l O 5. 1.3 x l O 1. 4.7. F ...
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12

A d s o r p t i o n - D e s o r p t i o n Kinetics at the M e t a l - O x i d e - S o l u t i o n Interface

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Studied by R e l a x a t i o n M e t h o d s 1

2

Tatsuya Yasunaga and Tetsuya Ikeda 1

Institute of Science and Technology, Kinki University, Higashi-Osaka 577, Japan department of Chemistry, Faculty of Science, Hiroshima University, Hiroshima 730, Japan Chemical relaxation methods can be used to determine mechanisms of reactions of ions at the mineral/water interface. In this paper, a review of chemical relaxation studies of adsorption/desorption kinetics of inorganic ions at the metal oxide/aqueous interface is presented. Plausible mechanisms based on the triple layer surface complexation model are discussed. Relaxation kinetic studies of the intercalation/ deintercalation of organic and inorganic ions in layered, cage-structured, and channel-structured minerals are also reviewed. In the intercalation studies, plausible mechanisms based on ion-exchange and adsorption/desorption reactions are presented; steric and chemical properties of the solute and interlayered compounds are shown to influence the reaction rates. We also discuss the elementary reaction steps which are important in the stereoselective and reactive properties of interlayered compounds. The fast reactions of ions between aqueous and mineral phases have been studied extensively in a variety of fields including colloidal chemistry, geochemistry, environmental engineering, soil science, and catalysis (1-6). Various experimental approaches and techniques have been utilized to address the questions of interest in any given field as this volume exemplifies. Recently, chemical relaxation techniques have been applied to study the kinetics of interaction of ions with minerals in aqueous suspension (7). These methods allow mechanistic information to be obtained for elementary processes which occur rapidly, e.g., for processes which occur within seconds to as fast as nanoseconds (8). Many important phenomena can be studied including adsorption/desorption reactions of ions at electri fied interfaces and intercalation/deintercalation of ions with minerals having unique interlayer structure. In this paper, a review of the mechanistic information that has been obtained in chemical relaxation studies of reactions of ions with metal oxide minerals in aqueous suspensions is discussed. The 0097-6156/ 86/ 0323-0230507.00/ 0 © 1986 American Chemical Society In Geochemical Processes at Mineral Surfaces; Davis, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1987.

12.

YASUNAGA AND IKEDA

review

is

devided

Relaxation

Reaction

Summary

and

Chemical

of

ture,

the

The

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methods

and

3T

the

librium ter

P

;

RT _

_

RT

Δν,

P,T

and

ΔΜ a r e

of

constant

detection

tivity

of

milliseconds

In

electric

can be

conductivity and

to

at

the

been a

described

is

much f a s t e r 20 k V / c m .

this

of

apparatus

of

by

7 atm. The

means (b)

of

operating

ζ-potential the

Fe30it,

compounds

used

and

an

the the

time of

of the

Sample

}

;

and

parame­ remeans

were a -

and

compound

(7).

200

with It

The

the

conduc­

has

a

time

conductivity

occuring

ys.

of

of

atm.

electric time

as

(10).

of

on

the

the

the

by

changing

order

applied

strength

of

of

the

electric-field-jump

that

For

solenoid apparatus

of

this

the

under

15

detection

pressure-jump aqueous

suspension

particles

method

external The

system,

valve is

an

method.

metal-oxide

metal-oxide

are

mixed

nitrogen

gas

measured

by

ms. was

(11).

The m e t a l

silica-alumina,

oxides

used

andy-Al203.

γ-zirconium phosphates (HT),

conductivity order

measurement

stopped-flow

Preparation.

T1O2,

the

(9).

aqueous this

on

rise

0.1

same

electric

α-FeOOH,

hydrotalcite-like

J

equi­

The

suitable

apparatus

of

details

micro-electrophoresis

Materials

Fe2Û3,

dead

an

the

external

electric

elsewhere

perturbed

previously and

the

reactions

than

be

by is

of

The

elsewhere

apparatus

solution The

to

The

cannot

detected

described

electrolyte rapidly

found

±

1).

with

method w i t h

microseconds.

which

an some

occuring

pressure

applied

is

system

tempera­

volume,

methods,

strength).

by

pressure-jump

field

may b e

(Figure

details

bursting

can be

field

relaxation

field

parameter

equilib­

by

standard

altering

observed

reactions

The

using

have

can be

of Κ on

Materials

electric

Reactions

given

enthalpy,

rapidly

electric apparatus

constant

jump-relaxation

or

to

perturbations

are

by

signals

system

field

standard

electric-field-jump

detecting

small

equilibrium

changed

as

80 y s

Methods

pressure,

milliseconds.

of

The

the

applied

detection

constant

(5)

U

Pressure-jump

can be

relaxation

(3)

and

K

relaxation

such

the

reaction.

is

or

Apparatus. to

Kinetics,

ΔΗ

BE

(temperature,

seconds

Chemical

K

^

E x p e r i m e n t a l Methods (a)

of

and M a t e r i a l s ,

2

RT

;

involve

electric

3 P }T

moment

detection

Principles

Intercalation

of

^

equilibration of

231

ΔΗ

=

jHnK

ΔΗ,

(1)

Methods

Chemical Relaxation

31nK V

electric

(4)

dependences

pressure,

where

sections:

Experimental

Kinetics,

relaxation

(8).

five

(2)

Kinetics

Conclusions.

Principles

rium

into

Method,

Surface

A dsorption-Desorption

montmorillonite

(α-,

were

Layered

γ-ZrP),

(Mont),

zeolite

In Geochemical Processes at Mineral Surfaces; Davis, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1987.

T1S2, 4A

GEOCHEMICAL PROCESSES AT MINERAL SURFACES

232

(Z-4A),

and z e o l i t e

intercalation interlayer

space

of

three-dimensional were

no s i g n

the

equilibrium were

was c o n t r o l l e d

Surface In ion

Reaction

aqueous

(4).

concentration

equilibrated

to

(10-22).

preparation.

of

obtain A l l

The tem­

a t 25 ° C .

Kinetics

suspensions,

metal

One c a n d e s c r i b e on surface

stable

course

used

elsewhere

The

particles

very

the time

techniques

h after

by the

by the

of

formed

over

are described

f o r 24-72

diameters

particles

The a n a l y t i c a l

varied

patterns.

i s separated

T h e mean

small

of sedimentation

k i n e t i c measurements.

perature

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with

Such

distance

diffraction

zeolite

structures.

1 ym.

the

samples

The i n t e r l a y e r from X - r a y

the crystalline

cage

approximately

suspensions

H-ZSM-5.

was d e t e r m i n e d

oxides

have

amphoteric

the adsorption/desorption

hydroxyl

groups

(SOH) u s i n g

of H

properties and counter­

+

the following

mass

action

equations : in

t h e pH r a n g e

below

the

p H

z

p

c

ki S0H£

SOH k

S0H+

+

t h e pH r a n g e

H+

above k

(I)

2

A" ^

SOHt k_

in

+

the

A"

(II)

2

p H

z

p

c

3

SOH

a*-

SO"

+

H+

(III)

k-3 ki* SO"

where the 2,

p H

z

p

metal 3 , 4)

c

,

+

B+

^

A ~ , and B

oxide,

stand

+

an anion,

are the rate

equilibrium

SO"

are given

[S0H][H+] Κι

=

εψ -

a

n

ion

-

=

εψ

[SOH]

K

cation

"

K l

n

— [S0~][B ] +

)

=

4 n i o n

(4)

e

B

=

K*

n

t

ψ

P(~ > k T



&

5

β

— = k T

0

exp(

T

θ

x

f i

βψ

«p r

o > r "Ό 70 O n m m m m

O m O o x m

In Geochemical Processes at Mineral Surfaces; Davis, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1987.

+

Mont

2

d

d

NH+/H (80)

^

When

^

the

dash

2

2

constants

3

Aperture

or

k

these

2

3

2

x

k 3

are

3

made,

an

2

+k 3

);

rate

S(A)M

modified

intrinsic

/(k_

should

+k- k ) .

-*k

systems

+k-ik-

ratio.

for

2

distance.

Silica-alumina

Rate

2

3

+k_i),

k-3 - > k _ i k - k - / ( k k

k-x + k - i k _ / ( k

constants

approximation

rate

be

S(M)A;

appears

x

2

S(A)M

3

or

in

this

2

3

2

+k_i

2

column and 2

3

+k ),

+k_i),

the

S (M) A

and

S (A) M

ki+ kik /(k +k_!k-

S(M)A; ki +k k k /(k k

follows:

constants.

and

as

intermediate

6 . 5

1800

700

has

e

6 . 5

the

e

e

e

6 . 5

380

15

800

been

220

650

represents

for

200

applicable.

580

440

85000

4 . 5 e

e

0.73

2100

0.48

4 . 5

1.8

e

4 . 5

1.3 0.28

1.3

e

0.42

4.5 4 . 5

1600

3.7

2800

3.7 2.3

28 1.8

12000

not

(continued)

18000

V

steady-state

d

expression

The

a

+

NH+/H (160)

+

NHt/H+(40)

H-ZSM-5

L-arg

3

+

+

(CH ) NHI/Na

7

+

5

3

n-C H NHT/Na

2

C H NHt/Na

3

CH NHt/Na

+

Z-4A

NH|/Na

Table

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GEOCHEMICAL PROCESSES AT MINERAL SURFACES

250

is

apparent

calate seen

from

more

that

steric

the trend

factors

step)

rate

step)

effects.

constants

properties

of

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for

the L

(levorotatory)

minerals.

To test

intercalation

in

interlayer Table

V.

suggests with (b)

that

is

a topic

volume

spacing

of

(see,

based

interest

Voudrias

to L-ornithine

However,

this

of

a

reaction

catalyst.

determined

k

The

rate

kinetic

constants

responsible product ated

with study

from

show t h a t step

this

(step

the observed suggests

study

of Acidic

3),

play

activities

interlayer

turn

depend

obtained H

+

(22) as

is

slowly

from

the relaxation

a r e summarized

Lknown.

i n the absence

reaction

i n the

technique

was

3

^

i n Table

(steps hours

the rate

Urea

The

1 a n d 2)

hydrolysis. over

V.

(XIII)

are

T h e much and not

limiting

slower

associ-

step. size

the c a t a l y t i c

potential

role

on I n t e r c a l a t i o n protons

V.

bound

in their and a c i d i c

kinetic

different

i n Table

S(Na)

i n determining

The c a t a l y t i c

at three

of

is well

and molecular

on t h e s i l i c a - a l u m i n a r a t i o

i n H-ZSM-5

this

spacing

zoelite,

an important

(23).

steps

occuring

Properties

of t h e H-ZSM-5

framework

by arginase,

are given

catalyzed

i n the environment.

Effect

in

Orn or

of

minerals

mineral

contaminants

elsewhere

k

relaxations,

that

nature.

The h y d r o l y s i s

S(Na-Orn*Urea) ^

may b e i m p o r t a n t

(c)

of

of organic

2

contaminant

channels

in

the pressure-jump

intercalation

f o r the observed

release

This

associated

acids

2

data

summarized

L-histidine

H 0

+

using constants

are

for

for the hydrolysis

^s(Na)Arg+-"^

Arg ~

rate

very

isomer

layered

(19):

ki S ( N a ) ^

of

The r a t e

and d i s c u s s e d

systems

optical

The a b i l i t y

only

alkyl-

of L - and D - h i s t i d i n e

amino

reactions

using

follows

living

r e a c t i v i t y may b e

place

The mechanism

t o be as

of

properties

and urea, catalyzed

of montmorillonite

the

the chemical

investigation

of

steric

important.

and Reinhard).

takes

of

that

(21).

Phenomena.

hydrolysis

arginine

presence

be

enhanced

the L-form

The

step

(deintercalation

value

a

the rates

on t h i s

chemical of

ion.

compound was i n v e s t i g a t e d

the s l i g h t l y

current e.g.,

the p K

technique

is

both

reflecting

k_i

13, suggesting

hypothesis,

Intercalation

to catalyze

constant

the D (dextrorotatory)

relaxation

selection

Catalytic

with

of

and the subsequent i o n -

the stereoselective

relative

natural

surfaces

over

this

A s shown

site

for the preference

i n t o HT l a y e r e d

pressure-jump

and

with

the exchanging

i o n may a l s o

explanation

may b e a s s o c i a t e d

the

better

i n Figure

inter12 i t

(the i n t e r c a l a t i o n

2

the rate

the exchanging

A possible

of

to

i s a function

the c a t i o n volume,

hand,

to correlate

ammonium i o n a s shown

are able

From F i g u r e

reaction

k i and k

with

ions

phase.

to an adsorption

correlate

On t h e o t h e r

seems

the smaller

the solid

i n the overall

the aperture

exchange

data, into

and chemical p r o p e r t i e s

intercalation through

these

favorably

Phenomena.

and a c i d i c

properties

studies

o f H-ZSM-5

The rate ratios

The mechanism t h a t

in

constants

of exchange

silica-alumina

In the

on t h e a l u m i n o s i l i c a t e

catalytic

(23).

of

o f NH"J" f o r

(40,

8 0 , 160)

was p r o p o s e d

follows:

In Geochemical Processes at Mineral Surfaces; Davis, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1987.

is

Adsorption-Desorption

Kinetics

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YASUNAGA AND IKEDA

In Geochemical Processes at Mineral Surfaces; Davis, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1987.

GEOCHEMICAL PROCESSES AT MINERAL SURFACES

252

S (H)

where of

+

^

the intermediates

S(NH\)

in

this

of

the ion-exchange

study,

the

were

trend

reaction.

t h e same

acidity

values

silica)

This

i o n i s not appreciably properties

reactivity

and Conclusions

In

r e v i e w we h a v e

this

successfully

mineral/water

charged, theory

and

shown

reaction

cations

have

have

ions

also

been

illustrated have

been

steric

hence

to the

silica-alumina where

play

of the

the inter­

(e.g.,

NR*t) t h e

an important

role

ions double

of

studies

properties

anions of

of inorganic and interlayer

information

on the rates

catalytic

layer

obtain

adsorbing

kinetic

predominately

and chemical

of influence

to

with

adsorption/desorption

and s p e c i f i c a l l y Relaxation

canbe

occuring at

electrical

c a n be combined

The mechanistic

methods

of inorganic

oxides,

and ion-exchange

having

stereoselective,

relaxation

of reactions

Mechanisms

discussed.

minerals

degrees

with

data

counterion,

reviewed.

that

varying

Minerals have

with

chemical

metal

and rate

intercalation/deintercalation organic

a

hindered

For reactions

mechanisms.

been

result

studied;

to the acidity

site

t h e dynamics

nonporous

electrolyte

ratios

i n systems

sterically

that

to study

and equilibrium

proton,

that

t o be

V, the interlayer

corresponds

3

scheme

results

of the minerals.

interface.

essentially

plausible of

applied

was found

from

related

of the ion-exchange

Summary

the

i n going

implies

chemical

the relative

the kinetic

i n Table

of k i and k _

calating in

i n the reaction

+

for a l l silica-alumina

(more

site.

(XIV)

observed

A s shown

o f 40 t o 1 6 0 , and i s d i r e c t l y

ion-exchange

H+

to interpret

i . e . , the relaxation

of increasing

increasing ratio

+

S(H)NH"t a n d S ( N H O H

Equation XII are not required

spacings

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N H l ^

of ions of

surface

obtained has and minerals

reaction.

and i o n - s i e v e

properties

discussed.

Acknowledgments The

authors

critical

are grateful

reading

t o Kim F . Hayes a t

of the manuscript

Stanford

and f o r helpful

University for

discussion.

Literature Cited 1.

Allen, L. H.; Matijevic, E . ; Meites, L. J. Inorg. Nucl. Chem. 1971, 33, 1293-1299. 2. Huang, C. P.; Stumm, W. J . J. Colloid Interface Sci. 1973, 43, 409-420. 3. James, R. O.; Healy, T. W. J. Colloid Interface Sci. 1972, 40, 42-52, 53-64, 65-81. 4. Davis, J . Α.; Leckie, J . O. J . Colloid Interface Sci. 1978, 67, 90-107. 5. Davis, J . Α.; Leckie, J . O. J. Colloid Interface Sci. 1980, 74, 32-43.

In Geochemical Processes at Mineral Surfaces; Davis, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1987.

12.

YASUNAGA AND IKEDA

6. 7. 8. 9. 10.

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11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23.

Adsorption-Desorption Kinetics

253

Whittinham, M. S.; Jacobson, A. J., Eds., "Intercalation Chemistry"; Academic Press: New York, 1982. Hachiya, K.; Ashida, M.; Sasaki, M.; Kan, H.; Inoue, T.; Yasunaga, T. J. Phys. Chem. 1979, 83, 1866-1871. Bernasconi, C. F. "Relaxation Kinetics"; Academic Press: New York, 1976. Tsuji, T.; Yasunaga, T.; Sano, T.; Ushio, H. J. Am. Chem. Soc. 1976, 98, 813-818. Ikeda, T.; Nakahara, J.; Sasaki, M.; Yasunaga, T. J . Colloid Interface Sci. 1984, 97, 278-283. Dolzhenkova, A. N.; Gevorkyan, Β. Α.; Vishnyakova, G. V. Obogasch. Rud. (Leningrad), 1973, 18, 31. Astumian, R. D.; Sasaki, M.; Yasunaga, T.; Schelly, Z. A. J. Phys. Chem. 1981, 85, 3832-3835. Astumian, R. D.; Schelly, Z. A. J. Am. Chem. Soc. 1984, 106, 304-308. Sasaki, M.; Moriya M.; Yasunaga, T.; Astumian, R. D. J. Phys. Chem. 1983, 87, 1449-1453. Mikami, N.; Sasaki, M.; Hachiya, K.; Astumian R. D.; Ikeda, T.; Yasunaga, T. J . Phys. Chem. 1983, 87, 1454-1458. Hachiya, K.; Sasaki, M.; Saruta, Y.; Mikami, N.; Yasunaga, T. J. Phys. Chem. 1984, 88, 23-27. Hachiya, K.; Sasaki, M.; Ikeda, T.; Mikami, N.; Yasunaga, T. J. Phys. Chem. 1984, 88, 27-31. Ikeda, T.; Sasaki, M.; Yasunaga, T. J . Phys. Chem. 1983, 87, 745-749. Ikeda, T.; Yasunaga, T. J . Phys. Chem. 1984, 88, 1253-1257. Mikami, N.; Sasaki, M.; Yasunaga, T.; Hayes, K. F. J. Phys. Chem. 1984, 88, 3229-3233. Ikeda, T.; Amoh, H.; Yasunaga, T. J . Am. Chem. Sco. 1984, 106, 5772-5775. Ikeda, T.; Yasunaga, T. J. Colloid Interface Sci. 1984, 99, 183-186. Kokotailo, G. T.; Lowton, S. L . ; Olson, D. H.; Meier, W. M. Nature (London), 1978, 272, 437-438.

RECEIVED June

18, 1986

In Geochemical Processes at Mineral Surfaces; Davis, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1987.