31
4.3 Preparation of Well-Ordered Single-Crystal Electrodes
Preparation of well-ordered, clean single-crystal electrode surfaces and their transfer to the cell without contamination is of crucial importance for electrochemical
experiments. Coupling of UHV characterization with electrochemistry has been
mainly attempted using the “most difficult” surface, namely, platinum, and only
after some time the results from various laboratories had started to agree. The major
breakthrough in preparation of well-ordered and clean single-crystal surfaces was
the so-called flame-annealing method developed by Clavilier et al. [8]. The crystal
(Pt, Pd, or Au) is annealed in a H 2 /O 2 flame, and small crystals (1–3 mm in diameter)
were quenched in pure H 2 O and transferred in the electrochemical cell. Larger crystals are cooled in clean H 2 or Ar, and while still hot, a drop of H 2 O was placed onto
the flat surface before the transfer to the cell [9]. More recently, Kolb and Vukmirovic
used more versatile induction heating method with the crystal in an Ar stream in
quartz tubing [10, 11]. Figure 4.4 shows annealing of Ru single-crystal with radio
frequency waves that quickly heat the crystal to high temperatures while the glass is
slightly warm. Another method was proposed by Wieckowski et al., in which the Pt
surface was protected by a monolayer of CO during transfer to the electrochemical
cell [12]. CO can be oxidized in a single sweep up to 1.1 V.
The overlayer structure that result when a species is adsorbed on a single crystalline surface depends on various factors, such as the relative sizes of the adsorbate
Fig. 4.4 Induction heating
of a Ru single crystal in a
quarts tubing in an argon
atmosphere. From Ref.
[11]
4.3 Preparation of Well-Ordered Single-Crystal Electrodes
4.3 Preparation of Well-Ordered Single-Crystal Electrodes
Preparation of well-ordered, clean single-crystal electrode surfaces and their transfer to the cell without contamination is of crucial importance for electrochemical
experiments. Coupling of UHV characterization with electrochemistry has been
mainly attempted using the “most difficult” surface, namely, platinum, and only
after some time the results from various laboratories had started to agree. The major
breakthrough in preparation of well-ordered and clean single-crystal surfaces was
the so-called flame-annealing method developed by Clavilier et al. [8]. The crystal
(Pt, Pd, or Au) is annealed in a H 2 /O 2 flame, and small crystals (1–3 mm in diameter)
were quenched in pure H 2 O and transferred in the electrochemical cell. Larger crystals are cooled in clean H 2 or Ar, and while still hot, a drop of H 2 O was placed onto
the flat surface before the transfer to the cell [9]. More recently, Kolb and Vukmirovic
used more versatile induction heating method with the crystal in an Ar stream in
quartz tubing [10, 11]. Figure 4.4 shows annealing of Ru single-crystal with radio
frequency waves that quickly heat the crystal to high temperatures while the glass is
slightly warm. Another method was proposed by Wieckowski et al., in which the Pt
surface was protected by a monolayer of CO during transfer to the electrochemical
cell [12]. CO can be oxidized in a single sweep up to 1.1 V.
The overlayer structure that result when a species is adsorbed on a single crystalline surface depends on various factors, such as the relative sizes of the adsorbate
Fig. 4.4 Induction heating
of a Ru single crystal in a
quarts tubing in an argon
atmosphere. From Ref.
[11]
4.3 Preparation of Well-Ordered Single-Crystal Electrodes