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© Springer Nature Switzerland AG 2020
R. Adzic, N. Marinkovic, Platinum Monolayer Electrocatalysts,
https://doi.org/10.1007/978-3-030-49566-4_4
Chapter 4
Studies of Electrocatalytic Reactions
4.1 Structural Effects in Electrocatalysis
Given the role the electrode surface plays in electrocatalytic reactions (vide supra),
the surface structure is expected to play a major role in determining the reaction
kinetics of electrocatalytic reactions. Upon formation of the surface, the coordination of surface atoms, interatomic distances, distance between adsorption sites, and
surface energy will depend on the plane exposed. The possible adsorption sites on
these planes are atop, bridge, and threefold and fourfold hollow sites. The atoms in
these sites have different coordination and interact differently with adsorbates. Even
lower coordination and stronger interaction with adsorbates is obtained with highindex planes or stepped surfaces. These usually consist of several atom-long terraces (3–20) separated by one atom step of same or different orientation. Before
studies with well-ordered single-crystal electrodes become possible, structural
effects in electrocatalysis were a controversial question.
4.2 Single-Crystal Electrodes
Most of the basic studies of electrocatalytic reactions nowadays are done using
single-crystal electrodes. These studies allow establishing the influence of surface
crystallography on the reaction kinetics, gaining information on the structure of
active sites, and determining structure of adlayers and adsorbate–substrate interactions. Electrocatalytic reactions are strongly surface structure sensitive [1]. The
structure of the top layer is responsible for the structural dependence of reaction
kinetics because reactant adsorption, intermediate formation, surface diffusion, surface recombination of intermediates, and product desorption all depend on the properties of the top layer of atoms. Studies of electrocatalysis with well-ordered
single-crystal surfaces started considerably later than in heterogeneous catalysis.
© Springer Nature Switzerland AG 2020
R. Adzic, N. Marinkovic, Platinum Monolayer Electrocatalysts,
https://doi.org/10.1007/978-3-030-49566-4_4
Chapter 4
Studies of Electrocatalytic Reactions
4.1 Structural Effects in Electrocatalysis
Given the role the electrode surface plays in electrocatalytic reactions (vide supra),
the surface structure is expected to play a major role in determining the reaction
kinetics of electrocatalytic reactions. Upon formation of the surface, the coordination of surface atoms, interatomic distances, distance between adsorption sites, and
surface energy will depend on the plane exposed. The possible adsorption sites on
these planes are atop, bridge, and threefold and fourfold hollow sites. The atoms in
these sites have different coordination and interact differently with adsorbates. Even
lower coordination and stronger interaction with adsorbates is obtained with highindex planes or stepped surfaces. These usually consist of several atom-long terraces (3–20) separated by one atom step of same or different orientation. Before
studies with well-ordered single-crystal electrodes become possible, structural
effects in electrocatalysis were a controversial question.
4.2 Single-Crystal Electrodes
Most of the basic studies of electrocatalytic reactions nowadays are done using
single-crystal electrodes. These studies allow establishing the influence of surface
crystallography on the reaction kinetics, gaining information on the structure of
active sites, and determining structure of adlayers and adsorbate–substrate interactions. Electrocatalytic reactions are strongly surface structure sensitive [1]. The
structure of the top layer is responsible for the structural dependence of reaction
kinetics because reactant adsorption, intermediate formation, surface diffusion, surface recombination of intermediates, and product desorption all depend on the properties of the top layer of atoms. Studies of electrocatalysis with well-ordered
single-crystal surfaces started considerably later than in heterogeneous catalysis.