Electrochemical activation of catalysis (2001)

Electrochemical Activation of Catalysis Promotion, Electrochemical Promotion, and Metal-Support Interactions Costas G Vayenas Symeon Bebelis University of Patras Patras, Greece University of Patras Patras, Greece Costas Pliangos Susanne Brosda University of Patras Patras, Greece University of Patras Patras, Greece Demetrios Tsiplakides University of Patras Patras, Greece KLUWER ACADEMIC PUBLISHERS NEW YORK, BOSTON, DORDRECHT, LONDON, MOSCOW eBook ISBN: Print ISBN: 0-306-47551-0 0-306-46719-4 ©2002 Kluwer Academic Publishers New York, Boston, Dordrecht, London, Moscow Print ©2001 Kluwer Academic/Plenum Publishers New York All rights reserved No part of this eBook may be reproduced or transmitted in any form or by any means, electronic, mechanical, recording, or otherwise, without written consent from the Publisher Created in the United States of America Visit Kluwer Online at: and Kluwer's eBookstore at: http://kluweronline.com http://ebooks.kluweronline.com To our parents and children FOREWORD I knew nothing of the work of C G Vayenas on NEMCA until the early nineties Then I learned from a paper of his idea (gas interface reactions could be catalyzed electrochemically), which seemed quite marvelous; but I did not understand how it worked Consequently, I decided to correspond with Professor Vayenas in Patras, Greece, to reach a better understanding of this concept I think that my early papers (1946, 1947, and 1957), on the relationship between the work function of metal surfaces and electron transfer reactions thereat to particles in solution, held me in good stead to be receptive to what Vayenas told me As the electrode potential changes, so of course, does the work function at the interface, and gas metal reactions there involve adsorbed particles which have bonding to the surface Whether electron transfer is complete in such a case, or whether the effect is on the desorption of radicals, the work function determines the strength of their bonding, and if one varies the work function by varying the electrode potential, one can vary the reaction rate at the interface I got the idea After that, it has been smooth sailing Dr Vayenas wrote a seminal article in Modern Aspects of Electrochemistry, Number 29, and brought the field into the public eye It has since grown and its usefulness in chemical catalytic reactions has been demonstrated and verified worldwide Electrochemical Activation of Catalysis contains a very full and detailed treatment of the mechanisms of electrochemical promotion It is likely to remain the standard work on this remarkable new technology; for who other than the present authors will write a book with such a background of authority in the field? What impressed me particularly was the wealth of high standard theoretical electrochemistry in discussions of the mechanism of NEMCA, for one seldom sees publications showing so much erudition in the theory of electrified surfaces On the other hand, the book contains a very full treatment, rich in examples, of the practical and experimental side of NEMCA and thus will be attractive to the chemists and chemical engineers who serve in corporate research laboratories It is likely to lead to advances in industrial vii viii FOREWORD techniques and its long term positive financial value would be difficult to overestimate Thus, there is a great deal of substance to this book on the electrochemical promotion of catalysis But the joy is that it has been set down in a very lucid way so that I seldom had to pause to scan a sentence a second time for meaning NEMCA is a triumph, and the latest in a series of advances in electrochemistry which have come about in the last 30 years, all of them situations which are not obviously electrochemical Examples include corrosion, metabolism, and (part of) photosynthesis Greece, thus far, has shown a wealth of electrochemical talent, e.g., in the work of Nikitas in adsorption studies, and the hope is that the excellent contributions of Professor Vayenas and his colleagues will continue to flourish and expand Given this abundance of expertise and the improvement the new method makes to chemical catalysis, I can only hope that Patras will continue to garner the support that it so richly deserves from the rest of the world John O’M Bockris PREFACE Electrochemical promotion, or non-Faradaic Electrochemical Modification of Catalytic Activity (NEMCA) came as a rather unexpected discovery in 1980 when with my student Mike Stoukides at MIT we were trying to influence in situ the rate and selectivity of ethylene epoxidation by fixing the oxygen “activity” on a Ag catalyst film deposited on a ceramic conductor via electrical potential application between the catalyst and a counter electrode Since then Electrochemical Promotion of Catalysis has been proven to be a general phenomenon at the interface of Catalysis and Electrochemistry More than seventeen groups around the world have made important contributions in this area and this number is reasonably expected to grow further as the phenomenon of electrochemical promotion has very recently been found, as analyzed in this book, to be intimately related not only to chemical (classical) promotion and spillover, but also to the “heart” of industrial catalysis, i.e metal-support interactions of classical supported catalysts Sincerest thanks are expressed to Professor J.O.’M Bockris, the leading electrochemist scientist and educator of the 20th century, for inviting me together with another electrochemist of comparable prominence, Prof B.E Conway, to write a Chapter on NEMCA in “Modern Aspects of Electrochemistry”, a Chapter which eventually grew into this book There are also several other individuals which I and my coauthors would like to thank cordially These include, in alphabetical order, Professor C Comninellis, Dr G Fóti, Professor G Haller, Dr K Howell, Dr F Kalhammer and Professor R Lambert for reading critically parts of the book and suggesting various important improvements Looking back to the past, sincerest gratitude is expressed to my parents, grandparents, daughters and other members of my family for their long love and support Also to my high school teacher Mr S Mantzaras and my PhD ix x PREFACE Thesis adviser and coadviser at the University of Rochester, Professors H Saltsburg and W.D Smith who taught me the hard work and the joy of research Also to my excellent teachers J Ferron and M Feinberg at the University of Rochester and to Gary Haller at Yale and Louis Hegedus, then at W.R Grace, both lifelong mentors and friends who introduced me into the beauty of catalysis and into the art and hardship of technical writing Also to Jimmy Wei, Bob Reid and Fred Putnam at MIT who taught me a lot and who, together with all the other ChE colleagues at MIT in the late seventies, created a stimulating intellectual and personal environment Sincerest thanks are also expressed to Professor Dr Lothar Riekert from Mobil and U Karlsruhe, a true thinker and lifelong mentor and friend and also to my dear colleague Professor Xenophon Verykios at Patras who first introduced me to the mysteries of metal-support interactions Many thanks are also expressed to Professors V Sobyanin and V Belyaev at Novosibirsk and Dr Anastasijevic now at Lurgi Their groups were the first (1990) to report NEMCA outside Patras The “loneliness” of NEMCA disappeared after a sabbatical year at Yale and our first joint publication in this area with Gary Haller I am indepted to him and his excellent coworker Dr Carlos Cavalca Cordial thanks are also expressed to Professor Richard Lambert and Professor Christos Comninellis, a prominent surface scientist and a prominent electrochemist whom I first met in 1993 and who both started working enthusiastically with their excellent groups on NEMCA The impact that the groups of Comninellis and Lambert had in shaping electrochemical promotion in the form we know it today was invaluable They both brought in numerous significant ideas described in this book Many thanks are also expressed to Professor Milan Jaksic who spent years in our lab and played a significant role in our first aqueous and Nafion NEMCA studies And to Dr P Stonehart who from the USA kept sending valuable samples and advice over the years Also to Professors S Ladas and S Kennou for their precious collaboration in the first XPS studies proving backspillover as the origin of NEMCA My coworkers and I feel deeply lucky and indebted to have met then Dr Fritz Kalhammer from EPRI Not only was EPRI’s financial support significant for strengthening our NEMCA work in Patras, but most importantly, Dr F Kalhammer, a former student of G.M Schwab, understood and described NEMCA as deeply, eloquently and concisely as nobody, in my opinion, had ever done before Fritz’s continuing support and friendship is gratefully acknowledged, as is that of Dr H Pütter of BASF, another prominent electrochemist whose continuing collaboration is most valuable, as is BASF’s, Dupont’s and EU’s continuing financial support Sincere gratitude is also expressed to my PhD students and postdoctoral coworkers, as well as the students of other colleagues mentioned above who PREFACE xi spent longer or shorter periods of time with us in Patras, building a good part of the contents of this book I am truly indebted to them They all did a nice job in establishing electrochemical promotion and elucidating various aspects of solid state electrochemistry In chronological order they are: Mike Stoukides (MIT, now at U Thessaloniki), Jim Michaels (MIT, now at Merck), Mark Manton (MIT, now at Shell), Roger Farr (MIT), Jim Mulready (MIT), Pablo Debenedetti (MIT, now at Princeton) And then at the U Patras: Ioannis Yentekakis, my coauthor of this book Symeon Bebelis, Stelios Neophytides Their three parallel PhD Theses in the late 80’s showed that NEMCA is a general phenomenon not limited to any particular catalyst, solid electrolyte or catalytic reaction Equally grateful I am to those who followed: Panagiotis Tsiakaras (now at the Univ of Thessaly), Christos Karavassilis, E Karasali, my coauthor in this book C Pliangos, Yi Jiang (now at Dalian), A Kaloyannis, M Makri (now at U Patras), C Yiokari and my youngest coauthor D Tsiplakides whose PhD Thesis significantly enriched the NEMCA literature, as did the Theses of Carlos Cavalca (Yale) and of Michel Marwood, E Varkaraki, J Nicole and S Wodiunig, all students of Professor Comninellis at EPFL, who spent time in our lab and showed truly extraordinary abilities Equally indebted I am to my postdoctoral coworkers P Petrolekas, O Mari’na, M Marwood, C Pliangos, M Makri and S Brosda who did a very nice job in advancing various aspects of electrochemical promotion and in guiding our younger PhD students G Pitselis, C Raptis, S Balomenou, A Giannikos, I Bafas, A Frantzis, D Polydoros, Th Bathas, A Katsaounis, I Constantinou and D Archonta Sincerest thanks and gratitude are also expressed to Ms Soula Pilisi, our priceless secretary for more than ten years, who typed this book and always worked diligently for our group in happy and in difficult times Costas G Vayenas NOMENCLATURE List of acronyms AES CSTR ECP EELS EP ESCA G/P HF HOMO HREELS ICP IR LUMO MSI NEMCA OCM PC PEEM PPR QMS RPC SCF SEP SERS SOFC Auger Electron Spectroscopy Continuous Stirred Tank Reactor Effective Core Potential Electron Energy Loss Spectroscopy Electrochemical Promotion Electron Spectroscopy for Chemical Analysis Galvanostat/Potentiostat Hartree-Fock model Highest Occupied Molecular Orbital High-Resolution Electron Energy Loss Spectroscopy In-situ Controlled Promotion Infra Red spectroscopy Lowest Occupied Molecular Orbital Metal-Support Interaction Non-faradaic Electrochemical Modification of Catalytic Activity Oxidative Coupling of Methane Point Charge Photo Electron Emission Spectroscopy Potential Programmed Reduction Quadrupole Mass-Spectrometer Retarding Potential Curve Self-Consistent Field Solid Electrolyte Potentiometry Surface Enhanced Raman Spectroscopy Solid Oxide Fuel Cell xiii xiv NOMENCLATURE STP STM TOF TPD UHV UPS XPS YSZ Standard Temperature and Pressure Scanning Tunneling Microscopy Turnover Frequency Temperature Programmed Desorption Ultra High Vacuum Ultra violet Photoelectron Spectroscopy X-ray Photoelectron Spectroscopy Yttria-Stabilized Zirconia abs ac, AC cpd dc, DC lhs o.c max pzc rhs rls she soe tpb absolute alternating current contact potential difference direct current left hand side open circuit condition, I=0 maximum value point of zero charge right hand side rate limiting step standard hydrogen electrode standard oxygen electrode three phase boundaries List of Symbols Symbol a A A C Ca D Meaning denotes adsorbed species oxygen activity electron acceptor adsorbate solid electrolyte surface area solid electrolyte-catalyst interface area gas exposed catalytically active surface area capacitance Carberry number defined in Eq (5.52) capacitance of the electrode/electrolyte interface surface concentration of backspillover species maximum surface concentration of backspillover species electron donor adsorbate Units Pa F F 568 Index Terms beta and beta” as sodium ion conductor gamma, as catalyst support Ammonia decomposition, electrochemically promoted synthesis, electrochemically promoted Ammonium polysulfide production electrochemically promoted Amphoteric adsorbates definition rules of Anode, etymology of Antibonding orbitals Anastasijevic Backspillover of ions electrochemically controlled formation of effective double layer thermody namics of Barbier Benzene hydrogenation, electrochemically promoted Bipolar cells electrochemical promotion of monolithic design multidot design multistripe design wireless configuration Bjerrum Blocking electrode Bockris Bode plot Boudart Bonding orbitals Butene isomerization, electrochemically promoted Calcium fluoride, solid electrolyte Capacitance charging current double layer, measurements of Carberry number Carbon dioxide adsorption hydrogenation Carbon monoxide adsorption hydrogenation Links 92 489 132 435 456 468 482 62 62 38 83 301 475 338 338 104 475 196 264 274 196 264 274 288 452 521 524 523 523 398 482 226 237 176 38 523 466 92 235 227 42 406 35 409 499 522 111 565 367 301 420 239 408 453 56 This page has been reformatted by Knovel to provide easier navigation 569 Index Terms oxidation Catalyst characterization dispersion preparation Catalyst-electrode catalytic characterization electrochemical characterization overpotential of potential of surface area of surface science characterization of Cathode etymology of Cell potential Nernst equation and work function Ceria electrochemical promotion with metal-support interactions Chemical cogeneration Chemical potential of adsorbates dependence on potential dependence on work function of gaseous reactants Chemisorption, see adsorption Comninellis electrochemical promotion of metal oxides electrochemical promotion of monolithic reactor permanent NEMCA Compensation effect electrochemical promotion induced isokinetic temperature Continuously stirred tank reactor, CSTR Conway Counter electrode Coverage, variation with work function Cyclic voltammetry Delmon, remote control mechanism Diffusion boundary layer in the gas phase length modeling of promoters on catalyst surfaces Diffusivity surface Links 133 385 118 487 116 190 390 487 119 121 123 123 119 189 95 139 314 203 348 428 489 98 308 309 309 312 374 524 176 166 166 128 111 117 281 233 101 227 124 199 503 195 227 199 503 This page has been reformatted by Knovel to provide easier navigation 442 570 Index Terms of promoters of oxygen Dinex, electrochemically promoted filter Dipole moment of adsorbates, measurements of initial Donicity Double layer capacitance of classical effective isotherm metal-gas metal-solid electrolyte Effective core potential Effective double layer characterization of isotherm kinetic expressions observations of with STM stability of Effectiveness factor of promotion computation of definition of Electrocatalysis and electrochemical promotion Faradaic efficiency of Electrochemical potential of adsorbates of ions Electrochemical promotion of catalysis definition limits of mechanism of modeling of origin relation to metal support interactions relation to promotion rules of Electrode etymology of potential of work function of Electron acceptor adsorbate chemical potential of definition of isotherm Electron donor adsorbate Links 195 195 199 199 525 503 24 134 280 133 233 233 233 7 306 7 269 239 271 271 315 271 271 189 306 316 259 225 315 351 503 505 505 180 180 308 499 10 180 189 315 189 509 283 303 123 138 505 271 503 509 203 340 208 24 309 This page has been reformatted by Knovel to provide easier navigation 571 Index Terms chemical potential of definition of isotherm Electron energy loss spectroscopy Electron spectroscopy for chemical analysis ESCA, see XPS Electronegative adsorbate see electron acceptor adsorbate Electrophilic behaviour definition of examples of global local rules of Electrophilic reactions definition of list of Electrophobic behaviour definition of examples of global local rules of Electrophobic reactions definition of list of Electropositive adsorbate, see electron donor adsorbate Electrostatic field of double layer strength of Energy of activation, see activation energy Enhancement factor, see Faradaic efficiency Enthalpy of adsorbates of adsorption coverage dependence work function dependence Entropy of activation compensation effect dependence on potential and work function for surface diffusion Epoxidation of ethylene, silver catalyzed of propylene Links 208 24 309 43 156 153 156 157 288 69 286 303 156 286 156 128 156 157 285 288 303 156 286 175 175 309 309 233 310 27 27 30 30 233 233 169 393 167 167 199 74 393 This page has been reformatted by Knovel to provide easier navigation 445 572 Index Terms Equations Arrhenius Butler-Volmer effective double layer isotherm effective double layer kinetics Helmholtz Langmuir Langmuir- Hinshelwood - Hougen-Watson (LHHW) kinetics Nernst prediction of Faradaic efficiency Temkin work function-overpotential work function-potential Ethane oxidation, electrochemically promoted Ethylene epoxidation on Ag/B"-A12O3 on 169 silver catalyzed classically promoted electrochemically promoted Ethylene oxidation, electrochemically promoted on iridium oxide/YSZ on Pt/YSZ on Pd/YSZ on Rh/YSZ on Pt on titania on Pt/B"-A12O3 435 on Pt/glass on ruthenium oxide/YSZ Faradaic efficiency definition of magnitude of in electrocatalysis magnitude of in electrochemical promotion prediction of Faraday and electrochemical terminology and his 1834 discovery and his laws of electrochemistry and solid electrolytes Faraday’s law deviations from for reactions with negative G and electrocatalysis and electrochemical promotion Fermi level of electrons Links 164 122 309 316 21 20 21 95 127 21 139 206 379 169 445 74 169 376 128 373 368 420 339 393 445 363 456 377 127 180 144 127 180 179 1 91 533 536 533 536 This page has been reformatted by Knovel to provide easier navigation 573 Index Terms and absolute potential distribution in a solid electrolyte cell and electrochemical potential and the rules of promotion and work function Fischer-Tropsch synthesis Fluorine ion conductors Foam, solid electrolyte Frumkin isotherm Gadolinia-ceria, solid electrolyte Galvani potential Gauss law Gold as counter electrode on YSZ and electrochemical promotion and metal-support interactions oxygen adsorption on, electrochemically promoted as reference electrode on YSZ Haber Haller Hartree-Fock wave functions High resolution electron energy loss spectroscopy, HREELS Highest occupied molecular orbital, HOMO adsorption energy dependence on of clusters, dependence on work function and work function Hydrocarbons chemisorption of on metals oxidation of, electrochemically promoted Hydrogen chemisorption of on metals evolution, electrochemically promoted oxidation of, electrochemically promoted Hydrogenation, electrochemically promoted acetylene benzene carbon dioxide carbon monoxide ethylene Illas and Pacchioni, quantum mechanical calculations Imbihl, high resolution photo-electron emission microscopy Infrared spectroscopy Inorganic melts as electrolytes Links 346 219 346 298 214 77 92 526 313 93 203 214 357 297 420 526 215 118 144 489 390 231 118 515 398 269 340 565 452 43 269 270 270 269 69 52 158 68 48 67 75 476 456 453 288 406 409 467 408 453 267 257 39 69 482 This page has been reformatted by Knovel to provide easier navigation 574 Index Terms oxidation of sulfur dioxide Interface gas-exposed catalytically active metal-gas and effective double layer metal-solid electrolyte Inverted volcano behaviour definition of examples of rules of Inverted volcano reactions definition of list of Interactions dipole-electric field lateral coadsorbate lateral electrostatic metal-support Iridium oxide electrochemical promotion of on titania, electrochemical promotion of Isokinetic point and compensation effect and electrochemical promotion Isotherms effective double layer electrochemical Langmuir Fowler-Guggenheim Frumkin Langmuir Janek Kalhammer Kelvin probe technique and work function measurement experimental details two-probe arrangement Kinetics effective double layer expressions Langmuir-Hinshelwood-Hougen-Watson negative order positive order promotional rules Kiskinova Ladas, XPS investigations of NEMCA Lambert, alkali promotion and electrochemical promotion XPS and AES Langmuir Lateral interactions Links 482 7 213 213 213 271 271 156 155 290 158 287 306 313 308 308 156 287 175 175 175 490 313 374 375 166 164 309 309 314 313 20 251 566 138 340 340 316 21 285 285 285 15 248 447 254 20 166 306 257 205 340 303 306 This page has been reformatted by Knovel to provide easier navigation 575 Index Terms attractive effective medium model for and ordered adlattices repulsive Lithium, promotion of carbon monoxide oxidation Long range effects Maleic acid hydrogenation Metal–support interactions and electrochemical promotion and electrophobic reactions mechanism of model for Metcalfe, modeling Methanation, electrochemical promotion of Methane oxidation and partial oxidation electrochemical promotion of dimerization reforming Methanol dehydrogenation electrochemical promotion of selectivity modification Methanol oxidation electrochemical promotion of 398 selectivity modification Microscopy photoelectron emission microscopy PEEM scanning electron microscopy, SEM scanning tunneling microscopy, STM Mixed conductors ceria and electrochemical promotion titania Monolith catalytic reactor electrochemical promotion of wireless configuration Multi-dot catalyst configuration Multi-stripe catalyst configuration Nasicon solid electrolyte electrochemical promotion with sodium ion conductor NEMCA, see electrochemical promotion NEMCA coefficient Nernst equation Nickel as fuel cell anode Links 266 306 264 266 74 189 481 490 499 490 507 316 406 293 409 308 470 410 403 404 400 257 113 114 428 420 420 259 489 489 524 525 525 524 523 440 440 152 95 319 97 This page has been reformatted by Knovel to provide easier navigation 576 Index Terms electrochemical promotion of YSZ cermets Nitrogen oxide chemisorption reaction, electrochemical promotion of NonFaradaic electrochemical modification of catalytic activity, NEMCA, see electrochemical promotion NonFaradaic processes Nyquist plot Oscillatory reactions carbon monoxide oxidation electrochemical promotion of Overpotential activation anodic cathodic cell concentration diffusion ohmic Oxidations, electrochemically promoted, list of reactions Oxidative coupling of methane Oxygen chemisorption energy of chemisorption on metals sticking coefficient of surface diffusivity of temperature programmed desorption of XPS of Oxygen ion backspillover of electrochemical potential of and electrochemical promotion promotional index of temperature programmed desorption of XPS of Pacchioni, quantum mechanical calculations Palladium electrochemical promotion of oxide Particulate matter combustion of, electrochemically promoted Dinex process European and US standards Permanent NEMCA Links 410 97 43 17 62 411 446 237 388 389 124 122 122 123 124 124 124 158 402 46 174 47 106 228 244 64 228 228 105 196 144 228 244 267 244 358 228 151 385 239 408 170 174 199 244 409 525 525 526 This page has been reformatted by Knovel to provide easier navigation 453 577 Index Terms characteristics potential for catalyst preparation Perovskites as cathode materials for soot combustion Photoelectron emission spectroscopy PEEM and electrochemical promotion imaging of work function Platinum electrochemical promotion of oxygen chemisorption on Point charges effect on binding energies of adsorbates for quantum mechanical calculations for simulation of electrochemical promotion Point of zero charge, pzc and absolute potential and effective double layer kinetics and work function Poisoning index Polarizable electrode Polarization, see overpotential Potential and Fermi level cell chemical of adsorbates chemical of electrons electrochemical of electrons extraction inner (Galvani) outer (Volta) work function equivalence Potential programmed reduction detection of adsorbed species and electrochemical promotion Pritchard Promoter definition electronegative electropositive lifetime sacrificial selection rules Promotion Links 176 177 96 526 257 258 128 46 228 144 64 244 170 269 269 269 333 309 333 148 117 212 123 307 213 215 203 203 215 203 205 237 237 189 23 23 194 193 298 118 215 212 215 218 345 565 23 510 This page has been reformatted by Knovel to provide easier navigation 174 578 Index Terms classical (chemical) electrochemical and metal–support interactions modeling of rules of Promotion index definition experimental values Propene epoxidation, electrochemically promoted oxidation, electrochemically promoted Proton conductors ammonia synthesis conductivity ethylene oxidation hydrogen oxidation list of electrochemically promoted reactions Quantum mechanical calculations electrochemical promotion with copper clusters with platinum clusters Quasi–reference electrodes Rate catalytic electrocatalytic turnover frequency Rate enhancement ratio in classical promotion definition in electrochemical promotion list of experimental values in metal–support interactions model predictions Reactor design bipolar continuously stirred tank reactor, CSTR differential fuel cell type monolithic type single chamber type single pellet type Redhead analysis esorption activation energy Falconer–Madix modification Reference electrode for the measurement of catalyst overpotential Reference electrode (cont.) Links 15 509 305 279 15 111 148 144 393 381 468 93 470 457 146 267 268 268 118 3 23 146 146 144 493 506 521 128 555 95 525 95 95 112 172 172 231 231 117 123 112 This page has been reformatted by Knovel to provide easier navigation 579 Index Terms in aqueous systems reversibility in solid electrolyte systems Rhodium dispersed catalysts electrochemical promotion of nitric oxide reduction oxide Rules of promotion derivation of undamental rules global rules local rules practical rules Ruthenium oxide electrochemical promotion of titania Sacrificial promoter definition electrochemical promotion lifetime Scanning tunneling microscopy, STM ordered adlattices oxygen adlattices platinum sodium adlattices spillover–backspillover Self–consistent field Selectivity definition electrochemical promotion modification of ethylene epoxidation hydrogenation of carbon monoxide and dioxide nitrogen oxide reduction Shift, spectroscopic chemical electrochemical Silver lectrochemical promotion of epoxidation on oxygen adsorption Smotkin isomerization proton conductors Sobyanin Sodium Links 476 342 117 495 17 414 17 368 123 130 417 414 144 368 417 286 299 285 296 298 377 374 193 194 193 510 264 261 261 262 259 269 17 136 169 168 399 409 136 419 399 245 246 144 169 171 393 232 466 466 564 This page has been reformatted by Knovel to provide easier navigation 400 580 Index Terms dipole moment electrochemical promotion with Sodium (cont.) list of electrochemically promoted reactions promotional index Sodium ion conductors beta and beta” alumina conductivity Nasicon Solid electrolytes applications conductivity fuel cells Solid oxide fuel cell, SOFC anodes catalysis in cathodes chemical cogeneration Spectroscopies AC Impedance spectroscopy Auger electron spectroscopy, AES High resolution electron energy loss spectroscopy, HREELS Infrared spectroscopy, IRS Surface enhanced Raman spectroscopy SERS Ultra violet photoelectron spectroscopy UPS X-ray photoelectron spectroscopy, XPS Spillover electrochemical promotion kinetic considerations remote control mechanisms Sulfur dioxide oxidation electrochemical promotion of vanadia melts Surface reconstruction Tafel plots Temperature programmed desorption, TPD detection of backspillover species of oxygen Thermodynamics of adsorption of spillover Three phase boundaries charge transfer at electrocatalysis at length, measurement of Links 26 131 209 170 223 435 145 145 91 93 440 435 94 92 96 97 98 96 99 410 237 254 43 39 256 69 69 255 244 199 101 10 101 482 33 125 228 228 306 104 499 114 115 243 This page has been reformatted by Knovel to provide easier navigation 581 Index Terms normalized length Time constants of NEMCA analysis of and backspillover prediction of Titania as catalyst support electrochemical promotion with metal–support interactions Transients galvanostatic potentiostatic Trasatti Turnover frequency, TOF of the catalytic reaction of the depletion of the promoting species Ultra–violet photoelectron spectroscopy UPS and work function detection of adsorbed species Vacuum level Vanadia melts electrochemical promotion with sulfur dioxide oxidation Vielstich Volcano type behaviour definition of examples of rules of Volcano type reactions definition of list of rules of Volta potential and electrochemical promotion Gauss Law Wagner Wolkenstein Work function and absolute potential and electrochemical promotion and cell potential Helmholtz equation of metals measurement of spatial variations variation with coverage Working electrode Links 243 198 198 200 489 420 491 491 128 210 335 198 374 193 193 139 255 203 482 482 565 156 154 289 155 290 156 287 289 203 214 279 353 138 138 24 139 138 222 24 218 This page has been reformatted by Knovel to provide easier navigation 582 Index Terms as catalyst overpotential of Yttria–stabilized–zirconia, YSZ Zirconia, yttria–stabilized, YSZ absolute potential of conductivity of nonstoichiometry of work function of Links 123 93 353 93 272 353 This page has been reformatted by Knovel to provide easier navigation ... chemical potential of specie j in the gas phase electrochemical potential of electrons electrochemical potential of electrons in the reference electrode electrochemical potential of electrons in... promotion of catalysis (EPOC) and in situ controlled promotion (ICP) have been also proposed, as synonyms to the NEMCA effect, for the description of the electrochemical activation of heterogeneous catalysis. .. Presence of Oxygen 8.1.4.4 Electrochemical Promotion of a Classically Promoted Rh Catalyst for NO Reduction by CO in Presence of The Use of Conductors 8.2.1 CO Oxidation on The Use of Mixed Conductors