166
Oxygen evolution reaction (OER) (cont.)
oxygen cathode, 60
palladium, 62
“peroxide” pathway, 58
platinum, 62
platinum metal electrodes, 60
Pt single crystals, 62
reaction mechanisms, 60
ring-disk measurements, 60
rotating ring-disk methodology, 60
structural and electrochemical
characteristics, 63
superoxide ion, 61
surface diffusion, 61
surface properties, 58
surface reactivity, 63, 64
thermodynamics, 59
Oxygen reduction, 51
Oxygen reduction activity, 17
Oxygen reduction reaction (ORR), 16, 57,
145, 157
activity and stability, 113
binding energy, 103
composition, 109
disk experiments, 104
kinetic current densities, 104, 108
kinetic currents, 103
kinetics, 107
lattice contraction, 110
low-coordination sites, 111
mixed-metal monolayer
electrocatalysts, 105
nonregistered atoms, 111
O/OH binding, 107
OH-OH repulsion, 107
O-O bond scission, 104
optimum, 103
polarization curves, 102, 106
Pt atoms, 107
Pt mass basis, 106
Pt/C catalysts, 106
Pt ML deposition, 101
Pt ML /Pd/C electrocatalyst, 105
XANES and in situ voltammetry, 106
Oxygen-containing species, 104
P
Palladium monolayer, 159
Palladium monolayer electrocatalysts
applications, 157
half-wave potentials, 159
hydrogen desorption, 159
monolayers, 158
Pd–O bonding, 159
volcano-type dependence, 157
Palladium–gold alloy nanoparticles, 153
Pd nanowires (NW), 111
Phosphoric acid fuel cell (PAFCs), 24
Plasma atomic emission spectroscopy, 90
Platinum, 153
Platinum content, 161
Platinum mass activity, 124
Platinum monolayer catalysts
activity and stability, 153
mass activity, 154
PdOH formation, 154
potential cycling, 153
Platinum monolayer electrocatalysts, 161
Polarization curve, 21, 97, 116
anodic and cathodic, 22
Polycrystalline electrodes, 44
Polycrystalline metal disk, 96
Polycrystalline platinum electrode, 36
Potential cycling, 153
Potential of zero charge (PZC), 3
Protic solvent systems, 2
Proton exchange membrane (PEM), 20
Proton exchange membrane fuel cell
(PEMFC), 23, 68
Pt monolayer activity, 126
Pt monolayer catalysts, 117
Pt monolayer electrocatalysts, 161
approaches, 83
atomic structures and component
distributions, 91
categories, 101
characterization, 90
concept, 84, 101
delayed oxidation, 91
deposition method, 87
electrocatalysts possesses, 101
ethanol, 88
experimental setup, 85
metal-alloy surfaces, 84
morphology and structure, 90
morphology and thickness, 89
oxygen reduction reaction, 88
potential cycles, 89
redox exchange, 85
shape and composition, 87
shell, nanoparticle, 84
synthesize, 85
UHV chamber, 90
UPD monolayer formation, 87
Pt monolayer shell interactions, 161
Index
Oxygen evolution reaction (OER) (cont.)
oxygen cathode, 60
palladium, 62
“peroxide” pathway, 58
platinum, 62
platinum metal electrodes, 60
Pt single crystals, 62
reaction mechanisms, 60
ring-disk measurements, 60
rotating ring-disk methodology, 60
structural and electrochemical
characteristics, 63
superoxide ion, 61
surface diffusion, 61
surface properties, 58
surface reactivity, 63, 64
thermodynamics, 59
Oxygen reduction, 51
Oxygen reduction activity, 17
Oxygen reduction reaction (ORR), 16, 57,
145, 157
activity and stability, 113
binding energy, 103
composition, 109
disk experiments, 104
kinetic current densities, 104, 108
kinetic currents, 103
kinetics, 107
lattice contraction, 110
low-coordination sites, 111
mixed-metal monolayer
electrocatalysts, 105
nonregistered atoms, 111
O/OH binding, 107
OH-OH repulsion, 107
O-O bond scission, 104
optimum, 103
polarization curves, 102, 106
Pt atoms, 107
Pt mass basis, 106
Pt/C catalysts, 106
Pt ML deposition, 101
Pt ML /Pd/C electrocatalyst, 105
XANES and in situ voltammetry, 106
Oxygen-containing species, 104
P
Palladium monolayer, 159
Palladium monolayer electrocatalysts
applications, 157
half-wave potentials, 159
hydrogen desorption, 159
monolayers, 158
Pd–O bonding, 159
volcano-type dependence, 157
Palladium–gold alloy nanoparticles, 153
Pd nanowires (NW), 111
Phosphoric acid fuel cell (PAFCs), 24
Plasma atomic emission spectroscopy, 90
Platinum, 153
Platinum content, 161
Platinum mass activity, 124
Platinum monolayer catalysts
activity and stability, 153
mass activity, 154
PdOH formation, 154
potential cycling, 153
Platinum monolayer electrocatalysts, 161
Polarization curve, 21, 97, 116
anodic and cathodic, 22
Polycrystalline electrodes, 44
Polycrystalline metal disk, 96
Polycrystalline platinum electrode, 36
Potential cycling, 153
Potential of zero charge (PZC), 3
Protic solvent systems, 2
Proton exchange membrane (PEM), 20
Proton exchange membrane fuel cell
(PEMFC), 23, 68
Pt monolayer activity, 126
Pt monolayer catalysts, 117
Pt monolayer electrocatalysts, 161
approaches, 83
atomic structures and component
distributions, 91
categories, 101
characterization, 90
concept, 84, 101
delayed oxidation, 91
deposition method, 87
electrocatalysts possesses, 101
ethanol, 88
experimental setup, 85
metal-alloy surfaces, 84
morphology and structure, 90
morphology and thickness, 89
oxygen reduction reaction, 88
potential cycles, 89
redox exchange, 85
shape and composition, 87
shell, nanoparticle, 84
synthesize, 85
UHV chamber, 90
UPD monolayer formation, 87
Pt monolayer shell interactions, 161
Index