Physical Electrochemistry E-Book

Noam Eliaz

• Herausgeber: Wiley-VCH Verlag GmbH & Co. KGaA
• Kategorie: Wissenschaft und neue Technologien
• Sprache: Englisch

Seitenzahl: 965

Veröffentlichungsjahr: 2018

Beschreibung

This bestselling textbook on physical electrochemistry caters to the needs of advanced undergraduate and postgraduate students of chemistry, materials engineering, mechanical engineering, and chemical engineering. It is unique in covering both the more fundamental, physical aspects as well as the application-oriented practical aspects in a balanced manner. In addition it serves as a self-study text for scientists in industry and research institutions working in related fields. The book can be divided into three parts: (i) the fundamentals of electrochemistry; (ii) the most important electrochemical measurement techniques; and (iii) applications of electrochemistry in materials science and engineering, nanoscience and nanotechnology, and industry.
The second edition has been thoroughly revised, extended and updated to reflect the state-of-the-art in the field, for example, electrochemical printing, batteries, fuels cells, supercapacitors, and hydrogen storage.

Leseprobe

Physical Electrochemistry

Fundamentals, Techniques, and Applications

Noam Eliaz and Eliezer Gileadi

Second Edition

Copyright

Authors

Prof. Noam Eliaz

Tel Aviv University

Department of Materials Science &

Engineering

Room 121, Wolfson Building

6997801 Tel Aviv

Israel

Prof. Dr. Eliezer Gileadi

Tel Aviv University

School of Chemistry

Shenkarbuilding

6997801 Tel Aviv

Israel

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© 2019 Wiley‐VCH Verlag GmbH & Co. KGaA, Boschstr. 12, 69469 Weinheim, Germany

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Print ISBN: 978‐3‐527‐34139‐9

ePDF ISBN: 978‐3‐527‐34140‐5

ePub ISBN: 978‐3‐527‐34142‐9

oBook ISBN: 978‐3‐527‐34143‐6

Cover Design Formgeber, Mannheim, Germany

Dedication

Dedicated to our beloved wives, Dalia Papouchado and Billie Eliaz, for their love, continued support, encouragement, and patience. Without them, our scientific careers would not be what they have been, and this book would not have been written.

Preface

Physical electrochemistry deals with the theory of the double layer at the metal/solution interphase, the thermodynamics and kinetics (rates and mechanisms) of reactions and processes that involve electron transfer. It is important in many aspects of fundamental chemistry, physics, biology, and engineering. There are many applications of electrochemistry, including corrosion, electrochemical deposition, electroforming, electromachining and electropolishing, electro‐organic synthesis, biosensors, batteries, fuel cells, and supercapacitors.

In spite of its importance, physical electrochemistry is rarely included in the undergraduate curriculum of chemistry and engineering in universities around the world. This book aims to serve as a key textbook in undergraduate courses that deal with electrochemistry, and also as a reference source for graduate students, researchers, and engineers who have interest in the field. Admittedly, the book contains more than what could be taught in one semester. This is deliberate in order to allow some choice for the teacher to concentrate on aspects of the field that best fit the needs of the particular class. However, even covering one half or two thirds of the material in this book should provide students with some understanding of physical electrochemistry, the techniques applied, and at least one of the applications in which electrochemistry is involved, and facilitate the learning and understanding of some specific subject that may be needed later in his or her professional life. This book is also recommended as a text suitable for self‐learning, which could be used to introduce scientists and engineers who have not had an opportunity to participate in a formal course on electrochemistry to aspects of this field needed for their research and development.

The book can be divided into three parts: (i) the fundamentals of electrochemistry: the potentials of phases, the electrical double layer (EDL), electrode kinetics, single‐step and multistep electrode reactions, electrocapillarity, electrosorption, underpotential deposition (UPD), and single‐crystal electrochemistry; (ii) the most important electrochemical measurement techniques: cyclic voltammetry (CV), rotating‐disk electrodes, microelectrodes and nanoelectrodes, electrochemical impedance spectroscopy (EIS), and electrochemical quartz crystal microbalance (EQCM); and (iii) applications of electrochemistry in materials science and engineering, nanoscience and nanotechnology, and industry: corrosion, electrochemical deposition (electroplating of metals and alloys, electroless and electrophoretic deposition), nanoparticles and surfaces, electrocatalysis, electrochemical printing, and energy conversion and storage (batteries, fuel cells, supercapacitors, and hydrogen storage).

The first edition of this book was published by Wiley‐VCH in 2011. Following its success, we made our best efforts to revise and improve this book significantly by (i) shortening certain sections that we find less needed for students nowadays; (ii) updating and extending some chapters according to the state‐of‐the‐art in the field, for example, electrochemical printing, batteries, fuels cells, supercapacitors, and hydrogen storage; (iii) adding key illustrations (figures and tables); (iv) adding recommended references at the end of each chapter; etc. Thus, we believe that the second edition will be valuable also to those of you who have read the first edition.

When writing this book we took advantage of our long experience in teaching courses such as physical electrochemistry, corrosion engineering, and materials science and engineering. There are different criteria by which the quality of a textbook could be judged. From our point of view, the success or failure of this book will be judged by its ability to enhance and spread the teaching and use of physical electrochemistry, and establish it as the basis for graduate courses offered widely in universities around the world. We hope you enjoy reading our book and find it easy to follow and enriching!

July 2018

Noam Eliaz and Eliezer Gileadi

Tel Aviv, Israel

Symbols and Abbreviations

Symbols

a

empirical Tafel constant

V

a

i

activity of substance

i

mol m

−3

, mol kg

−1

, or mole fraction

A

affinity of a reaction

J mol

−1

A

exposed surface area

cm

2

A

p

area of the drop during the application of pulse in normal‐pulse polarography

m

2

b

Tafel slope

V decade

−1

b

a

Tafel slope of the anodic (oxidation) reaction

V decade

−1

b

c

Tafel slope of the cathodic (reduction) reaction

V decade

−1

B

o

Bond number

dimensionless

c

i

concentration of substance

i

mol m

−3

c

b

concentration of the electroactive species in the bulk of the solution

mol m

−3

c

s

concentration of the electroactive species at the surface (

x

 = 0)

mol m

−3

c

‡

concentration of the activated complex

mol m

−3

C

dl

double‐layer capacitance

µF cm

−2

C

H

the Helmholtz capacitance

µF cm

−2

C

L

the adsorption pseudocapacitance derived from the Langmuir isotherm

µF cm

−2

C

0

subsurface concentration of atomic hydrogen

mol m

−3

C

0R

summation of the subsurface concentration of hydrogen in interstitial lattice sites and reversible trap sites on the charging side of the sample

mol m

−3

C

φ

adsorption pseudocapacitance

µF cm

−2

d

distance between the tip of the Luggin capillary and the working electrode

m

d

distance between the two plates of a capacitor

m

D

diffusion coefficient

m

2

s

−1

D

eff

effective diffusion coefficient

m

2

s

−1

D

0

nozzle diameter

m

E

electrical potential

V

E

0

standard potential

V

E

app

applied potential

V

E

b

breakdown potential

V

E

corr

corrosion potential

V

E

max

the potential where the pseudocapacitance reaches its maximum value

V

E

mp

mixed potential

V

E

p

protection potential

V

E

pp

primary passivation potential

V

E

pzc

potential of zero charge

V

E

rev

reversible potential according to the Nernst equation

V

E

1/2

polarographic half‐wave potential

V

f

fugacity

atm

f

Frumkin parameter

dimensionless

f

0

resonance frequency

Hz

G

Gibbs free energy

J mol

−1

Δ

G

change in the Gibbs free energy

J mol

−1

Δ

G

solv

energy of hydration of a metal ion

J mol

−1

Δ

G

0

change in the standard Gibbs free energy

J mol

−1

Δ

G

0‡

the standard electrochemical Gibbs free energy of activation

J mol

−1

the change in the standard electrochemical Gibbs free energy

J mol

−1

the standard Gibbs free energy of adsorption for a chosen value of

θ

J mol

−1

I

current

A

I

ionic strength

m

or M

I

d

diffusion‐limited current in dropping mercury electrode

A

I

D

current at the disk of a rotating ring disk electrode

A

I

L

mass‐transport‐limited current

A

I

R

current at the ring of a rotating ring disk electrode

A

j

current density

A m

−2

j

a

net anodic current density

A m

−2

j

avg

average current density in pulse plating

A m

−2

j

c

net cathodic current density

A m

−2

j

ac

/

j

ct

activation‐controlled current density/charge‐transfer current density

A m

−2

j

cc

critical current density

A m

−2

j

corr

corrosion current density

A m

−2

j

dep

deposition current density

A m

−2

j

dl

double‐layer charging current

A m

−2

j

L

limiting current density

A m

−2

j

L,chem

chemically‐controlled limiting current density

A m

−2

j

max

the final steady‐state current density

A m

−2

j

p

applied peak current density

A m

−2

j

pas

passive current density

A m

−2

j

0

exchange current density

A m

−2

J

ss

permeation flux of hydrogen at steady state

mol m

−2

s

−1

k

rate constant for a homogenous reaction

depends on order

k

b

homogeneous rate constant for “backward” reaction

depends on order

k

f

homogeneous rate constant for “forward” reaction

depends on order

k

0

chemical (heterogeneous) rate constant at the reversible potential

Δ

φ

 = 0

m s

−1

k

s,h

heterogeneous rate constant at standard potential

m s

−1

K

equilibrium constant

dimensionless

K

‡

equilibrium constant for formation of the activated complex

dimensionless

l

characteristic length of rotating disk electrode

m

L

membrane thickness in electrochemical permeation test

m

L

characteristic length of a capillary surface

m

m

flow rate in dropping mercury electrode

kg s

−1

M

atomic mass

g mol

−1

n

number of electrons transferred per molecule

dimensionless

nF

charge transferred per mole of species

C mol

−1

N

rotation rate

rpm

N

collection efficiency of a rotating ring disk electrode

dimensionless

N

total number of atoms in a particle

dimensionless

p

i

partial pressure of the

i

th components

atm

p

r

vapor pressure of a drop of radius

r

atm

q

M

excess charge density on the metal surface

C cm

−2

q

S

excess charge density on the solution side of the interphase

C cm

−2

r

radius of the working electrode

m

r

the rate of change of the standard Gibbs free energy of adsorption with coverage

J mol

−1

r

cyl

radius of the RCE

m

R

F

/

R

ct

faradaic resistance/charge‐transfer resistance

Ω m

2

R

p

polarization resistance

Ω m

2

R

S

uncompensated solution resistance

Ω m

2

Re

Reynolds number

dimensionless

R

film

resistance of a nonconductive surface film

Ω m

2

t

time

s

t

drop time in polarography

s

t

lag_63%

time during charging transient when the current density reaches 63% of the final steady‐state current density

s

t

p

pulse duration in normal‐pulse polarography

s

t*

dimensionless pulse time in electroplating

dimensionless

T

thermodynamic (absolute) temperature

K

U

bond energy

J mol

−1

U

cyl

linear surface (peripheral) velocity of RCE

cm s

−1

U

hyd

hydration energy of ions in solution

eV

V

voltage drop

V

V

t

thermal voltage

V

v

potential sweep rate

V s

−1

v

heterogeneous reaction rate

mol m

−2

s

−1

v

characteristic velocity of rotating disk electrode

m s

−1

ν

stoichiometric coefficient

dimensionless

v

number of occurrences of the rate‐determining step in the electrode reaction

dimensionless

ν

eq

reaction exchange rate at equilibrium

mol m

−2

s

−1

Wa

Wagner number

dimensionless

w

mass of a corroded metal

g

x

distance

m

X

‡

activated complex

z

charge number, valence

dimensionless

Z

(

ω

)

impedance

Ω

Z

W

Warburg impedance

Ω

α

transfer coefficient

dimensionless

α

a

,

α

c

anodic/cathodic transfer coefficient

dimensionless

β

symmetry factor

dimensionless

β

a

,

β

c

anodic/cathodic symmetry factor

dimensionless

γ

surface energy

J m

−2

γ

i

the activity coefficient of substance

i

dimensionless

γ

±

mean activity coefficient

dimensionless

Γ

surface excess

mol m

−2

Γ

surface concentration

mol cm

−2

Γ

max

maximum surface concentration

mol cm

−2

δ

thickness of the Nernst diffusion layer

m

α

Δ

β

φ

the difference between the inner potentials between two different phases, α and β

V

∇

del, the gradient operator

dimensionless

ε

absolute permittivity (dielectric constant) of the medium

F m

−1

ε

r

relative permittivity of the medium

dimensionless

ζ

zeta potential

V

η

overpotential

V

η

dynamic (absolute) viscosity

kg m

−1

s

−1

η

a

anodic overpotential

V

η

c

cathodic overpotential

V

η

ac

activation overpotential

V

η

conc

concentration overpotential

V

resistance (Ohmic) overpotential

V

θ

opening angle of a rotating cone electrode

degree (°)

θ

partial/fractional surface coverage

dimensionless

κ

specific conductivity of the solution

S cm

−1

κ

reciprocal Debye length

m

−1

λ

solvent reorganization energy

J mol

−1

λ

c

capillary length

m

μ

i

chemical potential of substance

i

J mol

−1

μ

0

standard chemical potential

J mol

−1

electrochemical potential

J mol

−1

Π

two‐dimensional surface pressure

J m

−2

ρ

density

kg m

−3

ρ

reaction order

dimensionless

ρ

specific resistivity of the solution

Ω cm

σ

stored charge density

C m

−2

σ

surface tension

N m

−1

τ

c

time constant for the parallel combination of a capacitor and a resistor

s

τ

d

characteristic time constant for the diffusion process

s

τ

pp

total pulse time

s

υ

kinematic viscosity

m

2

 s

−1

φ

angle between the metal and the insulator

rad

φ

α

the inner potential of phase α

V

φ

‡

potential of the activated complex

V

φ

x

the potential at a distance

x

from the surface of the metal

V

φ

M

the electrode potential

V

φ

S

the potential in the bulk of the solution

V

Δ

φ

the potential difference across the interface

V

Δ

φ

rev

the value of Δ

φ

at the reversible potential

V

χ

dimensionless rate constant

dimensionless

ω

angular velocity

rad s

−1

Abbreviations

AC

alternating current

ACD

anomalous codeposition

AES

Auger electron spectroscopy

AFC

alkaline fuel cell

AFM

atomic force microscope

AO

atomic oxygen

BET

Brunauer–Emmett–Teller

BEV

battery‐electric vehicle

CE

counter electrode

CI

corrosion intensity

CMOS

complementary metal–oxide–semiconductor

CNT

carbon nanotube

CP

cathodic protection

CPE

constant phase element

CPR

corrosion penetration rate

CR

corrosion rate

CV

cyclic voltammetry

CVD

chemical vapor deposition

DC

direct current

DME

dropping mercury electrode

DMFC

direct methanol fuel cell

DPN

dip‐pen nanolithography

DPP

differential‐pulse polarography

EC

electrochemical capacitor

EcP

electrochemical printing

EDL

electrical double layer

EDLC

electrochemical double‐layer capacitor

E‐DPN

electrochemical dip‐pen nanolithography

EDS

energy dispersive spectroscopy

EFAB

electrochemical fabrication

EIC

environmentally induced cracking

EIS

electrochemical impedance spectroscopy

EMF

electromotive force

EN

electrochemical noise

EPD

electrophoretic deposition

EQCM

electrochemical quartz crystal microbalance

ESC

environmental stress cracking

EV

electric vehicle

EW

equivalent weight

FC

fuel cell

FE

faradaic efficiency

FIB

focused ion beam

FPN

fountain pen nanofabrication

FRA

frequency response analyzer

FTIR

Fourier‐transform infrared

HDME

hanging dropping mercury electrode

HE

hydrogen embrittlement

HER

hydrogen evolution reaction

HEV

hybrid electric vehicle

ICCP

impressed‐current cathodic protection

ICE

internal‐combustion engine

IHP

inner Helmholtz plane

LECD

localized electrochemical deposition

LIB

lithium‐ion battery

LPR

linear polarization resistance

LSV

linear sweep voltammetry

MCED

meniscus‐confined electrodeposition

MIC

microbiological corrosion

NHE

normal hydrogen electrode

NP

nanoparticle

NPP

normal‐pulse polarography

OCP

open‐circuit potential

OER

oxygen evolution reaction

OHP

outer Helmholtz plane

OPD

overpotential deposition

ORR

oxygen reduction reaction

PAFC

phosphoric acid fuel cell

PEM

polymer electrolyte membrane

PHEV

plug‐in hybrid electric vehicle

QCM

quartz crystal microbalance

RConeE

rotating cone electrode

RCylE

rotating cylinder electrode

RDE

rotating disk electrode

RDS

rate‐determining step

RE

reference electrode

RHE

reversible hydrogen electrode

RRDE

rotating ring disk electrode

SCC

stress corrosion cracking

SCE

saturated calomel electrode

SDME

static dropping mercury electrode

SECM

scanning electrochemical microscopy

SEI

solid/electrolyte interphase

SEM

scanning electron microscope

SGC

Stern–Geary coefficient

SHE

standard hydrogen electrode

SIMS

secondary ion mass spectrometry

SPE

solid polymer electrolyte

STM

scanning tunneling microscopy

SWP

square‐wave polarography

UME

ultramicroelectrode

UPD

underpotential deposition

VCI

volatile corrosion inhibitor

WE

working electrode

XPS

X‐ray photoelectron spectroscopy

XRD

X‐ray diffraction

ZRA

zero‐resistance ammeter

Useful Units and Conversions

Å

Angstrom

1 Å = 10

−10

 m = 10

−8

cm = 10

−4

µm = 10

−1

nm

Ah

Ampere‐hour

1 Ah = 3600 C

C

Coulomb

1 C = 1 A s

cal

calorie

1 cal = 4.1868 J

dm

decimeter

10 dm = 1 m

Eq

equivalent

1 Eq will neutralize 1 mol of H

+

or (OH)

−

ions

erg

erg

1 erg = 10

−7

J

eV

electron volt

1 eV = 1.60218 × 10

−19

 J

F

Farad

F ≡ C V

−1

 = A

2

 s

4

 kg

−1

m

−2

Hz

Hertz

1 Hz ≡ s

−1

J

Joule

J ≡ N m = kg m

2

 s

−2

kWh

kilowatt hour

1 kW h = 3600 kJ

L

liter

1 L = 1 × 10

3

 cm

3

= 1 dm

3

M

molal

mol kg

−1

mil

mil

1 mil = 0.001 in.

mpy

mils per year

1 mpy = 25.4 µm y

−1

M

molar

mol L

−1

N

Newton

N ≡ kg m s

−2

rad

radian

1 rad = 360/2π = 57.2958°

S

Siemens

1 S ≡ 1 A V

−1

 = kg

−1

m

−2

s

3

 A

2

V

Volt

V ≡ W A

−1

 = J C

−1

 = kg m

2

 A

−1

s

−3

W

Watt

W ≡ J s

−1

 = kg m

2

 s

−3

A

−1

°F

degrees Fahrenheit

°C = 5/9·(°F – 32)

°K

degrees Kelvin

°K = °C + 273.15

Ω

ohm

1 Ω ≡ 1 V A

−1

 = kg m

2

 s

−3

A

−2

Physical Constants1

c

speed of light in vacuum

2.99792 × 10

8

 m s

−1

e

elementary charge

1.60218 × 10

−19

 C

F

Faraday constant

9.64853 × 10

4

 C mol

−1

 = 23 060 cal mol

−1

V

−1

g

standard acceleration of gravity

9.80665 m s

−2

h

Planck constant

6.62607 × 10

−34

 J s

k

Boltzmann constant

1.38065 × 10

−23

 J K

−1

K

w

equilibrium constant of water

1.008 × 10

−14

 mol

2

L

−2

at 25 °C

N

A

Avogadro's number

6.02214 × 10

23

 mol

−1

R

molar gas constant

8.31447 J mol

−1

K

−1

v

tr

transverse velocity of sound

3.34 × 10

4

 m s

−1

in AT‐quartz

ε

0

permittivity of free space (electric constant)

8.85419 × 10

−12

 F m

−1

μ

q

shear modulus of quartz

2.947 × 10

11

 g cm

−1

s

−2

ρ

q

density of quartz

2.648 g cm

−3

Potentials of Reference Electrodes in Aqueous Solutions at 25 °C

Common name

Electrode

V versus SHE

Notes

Mercury/mercurous sulfate

(

MMS

)

Hg/Hg

2

SO

4

/0.5 M K

2

SO

4

+0.680

Useful for avoiding chloride contamination of the test solution

Mercury/mercurous sulfate electrode

(

MSE

)

Hg/Hg

2

SO

4

/saturated K

2

SO

4

+0.640

Useful for avoiding chloride contamination of the test solution

Calomel

Hg/Hg

2

Cl

2

/0.1 M KCl

+0.336

Better temperature stability than SCE

Copper/copper sulfate electrode

(

CSE

)

Cu/saturated CuSO

4

+0.316

Very robust, commonly used for cathodic protection

Normal calomel electrode

(

NCE

)

Hg/Hg

2

Cl

2

/1 M KCl

+0.280

Better temperature stability than SCE

Saturated calomel electrode

(

SCE

)

Hg/Hg

2

Cl

2

/saturated KCl

+0.241

The most common electrode in laboratory. Use of mercury introduces safety hazards. Potential decreases as the solubility of KCl increases at higher temperatures. Cannot be used above 50 °C

Saturated sodium calomel electrode

(

SSCE

)

Hg/Hg

2

Cl

2

/saturated NaCl

+0.236

Saturated silver/silver chloride

Ag/AgCl/saturated KCl

+0.197

Very easy to make, but light sensitive. Can be used up to 80–100 °C

Mercury/mercury oxide

(

MMO

)

Hg/HgO/1 M NaOH

+0.140

Good for alkaline solutions

Standard hydrogen electrode

(

SHE

)

H

2

/H

+

,

,

0.000

Not to confuse with the normal hydrogen electrode (NHE) that implies

,

E

0

 ≅ 0.000 V

Note

1

Taken from the CODATA Internationally Recommended 2014 Values of the Fundamental Physical Constants (

http://physics.nist.gov/cuu/Constants/

, last accessed July 12th, 2016).