Analysis of the hydrogen electrode reaction mechanism in thin-layer cells. 3. Study of hydrogen electro-oxidation by scanning electrochemical microscopy

作者：Brites Helu Mariela A; Fernandez Jose L^*

来源：Journal of Electroanalytical Chemistry, 2017, 784: 33-40.

DOI：10.1016/j.jelechem.2016.11.065

• Hydrogen oxidation reaction
• Scanning electrochemical microscopy
• Kinetic analysis
• Thin-layer cell
• Reaction mechanism

Scanning electrochemical microscopy (SECM) in the feedback mode was used to analyze the complete mechanism of the hydrogen oxidation reaction (hor). A general SECM equation was proposed to carry out the kinetic analysis of the dependences of the tip current (i(T)) on the substrate potential (E-S) and on the tip-substrate distance (d). This SECM equation involves the contribution of a thin-layer cell (TLC) with no aprioristic restrictions about the reaction mechanism. A dependence of the TLC current on E-S previously developed for the hor operating through the Tafel-Heyrovslcy-Volmer mechanism was included in the proposed SECM model. The domain of conditions where the equation properly reproduces the SECM responses was determined by contrasting the calculated i(T)(E-S, d) dependences with simulated curves obtained by a numerical method using varied kinetic and geometric parameters. The experimental conditions where the model can be used were explored by analyzing the hor on Pt. The present treatment provides a versatile tool for the application of SECM to the kinetic and mechanistic analysis of the hor, which can be easily adapted for the analysis of any multi-step electrocatalyzed reaction on infinite substrates.

• 出版日期2017-1-1