PEM fuel cell catalysts from nanoscopic precursors [Elektronische Ressource] : a comparative study / vorgelegt von Sachin Kinge

Kapre

Informations

• Publié par: rheinisch-westfalischen_technischen_hochschule_-rwth-_aachen
• Publié le: 01 janvier 2004
• Nombre de lectures: 25
• Poids de l'ouvrage: 12 Mo

Extrait

PEM-Fuel Cell Catalysts from Nanoscopic Precursors-
A Comparative Study



Von der Fakultät für Mathematik, Informatik und Naturwissenschaften
der Rheinisch-Westfälischen Technischen Hochschule Aachen
zur Erlangung des akademischen Grades eines
Doktors der Naturwissenschaften genehmigte Dissertation






Vorgelegt von
SACHIN KINGE, M.Sc.
aus Nasik, Indien






Berichter: Herr Univ. -Prof. Dr. rer. nat. H. Bönnemann
Herr Univ. -Prof. Dr. rer. nat. U. Simon
Herr Univ. -Prof. Dr. rer. nat. W. Stahl
Vorsitzender: Herr Univ. -Prof. Dr. rer. nat.D. Enders


Tag der mündlichen Prüfung: 22. Dezember 2004




Diese Dissertation ist auf den Internetseiten der Hochschulbibliothek online verfügbar.









































iva&aana baHmaita vyajaanaata |
iva&aanaaQVva Kailvamaaina Bataaina jaayanta ||
iva&aanana jaataaina jaIvainta |
iva&aana payantyaiBasaivaSantaIita ||
tatairya {painaYad 3.5.1























(He) knew Knowledge as “Brahma”, for

from Knowledge, indeed, spring all these

beings; having been born, they are
sustained by Knowledge, they move
towards and merge in Knowledge.

Taittir īya Upanisad 3.5.1

oMo``MooMUoOo\




















This work was independently carried out between August 2002 and October 2004 at the
Max Planck Institut für Kohlenforschung, Mülheim an der Ruhr, Germany.
ACKNOWLEDGEMENTS
Acknowledgments

The following work is accomplished under the direction and support of
Prof. Dr. rer. nat. H. Bönnemann, Max-Planck-Institute für Kohlenforschung
in Mülheim an der Ruhr.

I express deepest gratitude to Prof. Dr. H. Bönnemann for giving me an
opportunity to join his group and perform research in this fascinating theme. I thank him for countless
scientific and many friendly discussions. His unbridled support and encouragement have contributed a
lot in sustaining my efforts.

I thank Prof. Dr. U. Simon and Prof. Dr. W. Stahl (RWTH Aachen) for reviewing the thesis and
agreeing to be the co-examiners.

I am thankful to Prof. F. Schüth (Director, Max-Planck-Institute für Kohlenforschung) for admitting
me in this prestigious institute.

I thank Deutsche Forschungsgemeinschaft for financial support during this work.

I am indebted to Dr. K. Nagabhushana, for his hospitality at the inception of my stay in
Mülheim a. d. Ruhr. I thank him very much for his discussions, support and astute contributions to
lend finesse to every aspect of my work.

I specially thank Mr. R. Brinkmann for his countless suggestions during the work. And his crucial and
insightful guidance during handling electronic media.

I wish to extend my thanks to, Mr. W. Hofstadt for the delightful scientific discussions and for in-time
help in and out side the lab.

Special thanks to my colleagues Dr. Wen Fei, Ms. S. Botha, Mr. M. Feyer, Ms. Esther Böß, Dr. G.
Khelashvilli, Dr. W. Brijoux and Dr. Nina Matoussevitch for cheerfulness and forbearance throughout
my work. For keeping my spirits up and enriching me.

I express my special gratitudes to Prof. A. De Battisti (University of Ferrara, Italy) and my friend
Dr. Christian Urgeghe (University of Ferrara, Italy) for important contributions in this work

i ACKNOWLEDGEMENTS


To Prof. Dr. J. Behm (University Ulm) and his group members, Dr. J. Kaiser, Dr. Z. Zusys for the
electrochemical measurements, and XPS studies.

I am very much thankful to Prof. K. Sundmacher ( MPI für Dynamik komplexer technischer Systeme,
Magdeburg) and Ms. T. Vidakovic for critical electrochemical analyses of the catalysts.

To Dr. C. Weidenthaler, I owe especially. For her innumerable XRD, XPS measurements and many
informative discussions. I thank her for her editorial judgements and important suggestions during
writing this draft.

To, Mr. A. Dreier, Dr. Tesche, Mr. B. Spliethoff for TEM, Mr. H. Bongard for SEM analyses and Mr.
W. Schmidt for TGA-DSC analyses of colloids and catalysts.

I am especially thankful to my previous scientific colleagues Mr. R. Barmeyer, Dr. F. Frank, Dr. K.
Merz for inspirations and friendly help during my stay in Bochum.

I also thank Saurav, Shashi, Rajib, Mahuya, Kallol, Chandan, Sumit, Sauman, Tapan, Urmila, Anjana
Devi, Mr. Basak and family, Padmini, Mamatha, Suchismita, Aruna for the friendly environment.

I extend my thanks to my close friends Manoj, Sheshadri, Tushar, Sandip, Kalidas, Ganesh.

And expressly to Kapre family and other well wishers in India.

I specially thank my loving parents, my caring brother, Parag, for their immeasurable support and
eminent understanding throughout the years.

To, Ruta, for being mine, sharing pleasant moments and caring. For suggestions, scientific discussions
through out this work and careful checking of the manuscript, I thank her.
ii
















ipaya Aa[ baabaasa....................
To my dear parents.............























`-M


CONTENTS


CONTENTS


CHAPTER 1
1 INTRODUCTION
1 1.1 General
2 1.2 Physical properties of nanomaterials and their significance
3 1.3 General description of the PEMFC and DMFC
4 1.4 Electrode reactions and Electrocatalysts in PEMFC and DMFC
7 1.5 Precursor concept of colloidal (fuel cell) catalysts preparation
7 1.6 Nanocluster preparation methods
8 1.7 Salt reduction methods
11 1.8 Goal of the work
12 1.9 Outline of the thesis
13 1.10 Bibliography

CHAPTER 2
17 METHODS OF NANOPARTICLE CHARACTERIZATION
17 2.1 General
17 2.2 TEM
20 2.3 EDX
22 2.4 SEM
23 2.5 Powder-Diffraction (XRD)
26 2.5.1 Vegard’s law
26 2.6 X ray photoelectron spectroscopy (XPS)
27 2.7 Gas adsorption
29 2.8 The Rotating Disk Electrode
31 2.8.1 CO-stripping voltammetry
34 2.9 Differential Electrochemical Mass Spectrometry (DEMS)
36 2.10 Synopsis
37 2.11 Bibliography


ICONTENTS
CHAPTER 3
CONDITIONING; COMMERCIAL VULCAN SUPPORT AND PT-ETEK,
PTRU-ETEK CATALYSTS 39
3.1 General 39
3.1.1 Conditioning of the supported catalysts 40
3.2 Description of the apparatus 42
3.3 Commercial Vulcan XC 72 R support characterization 42
3.4 Commercial Pt and Pt/Ru ETEK-catalysts characterization 43
3.5 Synopsis 46
3.6 Bibliography 47

CHAPTER 4
WET CHEMICAL SYNTHESES OF COLLOIDAL CATALYSTS 49
4.1 Wet chemical synthesis 49
4.2 Synthesis in organic solvents 49
4.3 Borohydride reduction method 50
4.3.1 Tetraalkylammonium triorganohydroborate reduction method 50
4.3.1.1 The NR X amount required for stabilization 50 4
4.3.1.1.1 Characterization 53
4.3.1.2 “Reverse addition” for particle size control 55
4.3.1.3 Synthesis of Pt Ru colloid by NR (BEt H) reduction method 50 50 4 3 57
4.3.1.3.1 Characterization of colloid 8 59
4.3.1.3.2 The optimum amount of NR X required 61 4
4.3.2 LiBH as the reducing agent 4 63
4.3.2.1 Pt/Ru (1:1) colloid (11) according to Y. E. Sung et al. 63
4.3.2.1.1 XRD, XPS and NMR analysis 63
4.3.3 LiBEt H reduction method 3 65
4.3.4 Synthesis of THF stabilized colloids via KBEt H reduction 68 3
4.3.4.1 General 68
4.3.4.2 Synthesis of [Nb·0.3THF] colloid (15) x 69
4.3.4.2.1 Characterization of (15) 69
4.3.4.3 Synthesis of [V·0.3THF] colloid (16) 74 x
4.4 Colloidal preparation via decomposition of organometallic precursors
and reductive stabilization 75
II