Program

1^st day. The bases of cyclic voltammetry

Class, 8:30 – 12:30 am (Cyrille Costentin)

• Welcome to CVIS
• Cyclic voltammetry of fast one-electron transfers (Nernstian responses)
• Introduction to dimensionless formulations and to educated simulations
  • One-electron transfer to molecules immobilized on the electrode
  • One-electron transfer to free moving molecules
• Technical aspects
  • The cyclic voltammetry experiment. Cell, electrodes and instrument
  • Faradaic and double layer charging currents
  • Ohmic drop. Resistance compensation
• Successive one-electron transfers vs. two-electron transfers
• Cyclic voltammetry of slow electron transfers
  • Immobilized and free moving reactants (investigating electron transfer kinetics by means of cyclic voltammetry)
  • Linear (Butler-Volmer) and non-linear (for outersphere, concerted dissociative and concerted proton coupled electron transfers) rate laws

Laboratory, 2:00 – 6:00 (or more) pm (Cyrille Costentin and Cédric Tard)

• Cyclic voltammetry of a Nernstian system (e.g. anthracene in an aprotic solvent)
• Ohmic drop and ohmic drop compensation with dummy and real cells
• An example of slow electron transfer

2^nd day. Coupled chemical reactions

Class, 8:30 – 12:30 am (Marc Robert)

• The EC reaction scheme
  • Fast electron transfer, pure kinetic conditions
  • Governing equations, reaction profiles (reaction-diffusion layer)
  • Transitions from reversibility to irreversibility, determining standard potential and follow-up reaction rate constant
  • Zone diagram, travelling through the zone diagram
  • Competition between diffusion, chemical reaction and slow charge transfer
  • Concerted processes: competition between stepwise and concerted reactions, concerted proton-coupled electron transfers
• Other case: dimerization

Laboratory, 2:00 – 6:00 (or more) pm (Marc Robert and Cédric Tard)¹

• Examples of EC mechanisms
  • 2-chloroanthracene in N,N’-dimethylformamide (EC first order, determination of standard potential and follow-up reaction rate constant)
  • Benzaldehyde (in ethanol at pH 12) (ECdim, determination of standard potential, electron transfer standard rate constant and dimerization rate constant)
• Examples of concerted cleavages
  • Benzyl chloride (a concerted cleavage with a transfer coefficient close to 0.3)
  • Trichloroacetonitrile (a concerted cleavage with a sticky interaction between fragments)

3^rd day. Catalytic systems

Class, 8:30 – 12:30 am (Cyrille Costentin)

• Homogeneous systems
  • Principle: 1e-1 step reaction: zone diagram
  • Catalytic Tafel plots
  • Benchmarking of catalysts
  • Multi electron-multi steps catalytic reactions, case of 2e – 2 step reactions
• Catalytic films
  • Monolayer coatings
  • Multilayer coatings

Laboratory, 2:00 – 6:00 (or more) pm (Cyrille Costentin and Cédric Tard)

• Catalysis of electrochemical reduction of CO₂ with Fe⁰tetraphenylporphyrin (Fe⁰TPP) as catalyst (in N,N’-dimethylformamide)
• Investigation of different parameters influencing the catalytic response: scan rate, addition of acid
• Analysis of the mechanism, catalytic Tafel plot

4^th day. Redox enzymes

Class, 8:30 – 12:30 am (François Mavré)

• Introduction to the cyclic voltammetry of redox enzymes
• The ping-pong mechanism
• Cyclic voltammetry of homogeneous redox mediated enzyme catalysis
• Transposition to immobilized systems
• How the Michaelis-Menten kinetics shows up in cyclic voltammetry
• Illustrating examples of more complicated mechanisms
• Mediated versus direct enzyme electrochemistry

Laboratory, 2:00 – 6:00 (or more) pm (François Mavré)

• Cyclic voltammetric study of the redox mediated catalytic oxidation of glucose by glucose oxidase in homogeneous solution
• Investigation of the different parameters influencing the catalytic response
• Experimental approach of the redox mediated catalytic oxidation of glucose by a monolayer of glucose oxidase immobilized on an electrode surface

5^th day. Questions from the floor

9:00 – 12:30 am

Cyrille Costentin, François Mavré, Marc Robert, Cédric Tard and Niklas von Wolff answer questions from the group.