Evaluation of the catalytic performance of gas-evolving electrodes using local electrochemical noise measurements.

Characterization of gas evolution reactions at the electrode/electrolyte boundary is often difficult due to the dynamic behavior of interfacial processes. Electrochemical noise measurements determined by scanning electrochemical microscopy were used to characterize Cl(2) evolution at gas-evolving electrodes (GEEs). Analysis of the electrochemical noise is a powerful method to evaluate the efficiency of the catalyst layer at a GEE.

Analysis of large experimental datasets in electrochemical impedance spectroscopy.

An approach for the analysis of large experimental datasets in electrochemical impedance spectroscopy (EIS) has been developed. The approach uses the idea of successive Bayesian estimation and splits the multidimensional EIS datasets into parts with reduced dimensionality. Afterwards, estimation of the parameters of the EIS-models is performed successively, from one part to another, using complex nonlinear least squares (CNLS) method.

Electrochemical characterisation of copper thin-film formation on polycrystalline platinum.

Electrochemically formed thin films are vital for a broad range of applications in virtually every field of modern science and technology. Understanding the film formation process could provide a means to aid the characterisation and control of film properties. Herein, we present a fundamental approach that combines two well-established analytical techniques (namely, electrochemical impedance spectroscopy and electrogravimetry) with a theoretical approach to provide physico-chemical information on the electrode/electrolyte interface during film formation.

Towards a detailed in situ characterization of non-stationary electrocatalytic systems.

A complementary combination of cyclic voltammetry, impedance spectroscopy and quartz crystal microbalance techniques was used to: (i) control the assembly of a model electrocatalytic system consisting of monolayer and sub-monolayer amounts of Ag and Pb on a Au electrode, (ii) evaluate the system performance for the reduction of NO(3)(-) and (iii) study the disassembly of the electrocatalytic system to explore any changes which occurred during the assembly and/or catalytic stages. Physical models of the electrochemical interface (described in terms of equivalent electric circuits) at all stages are found to be considerably different but consistent with each other. Deposition of the Ag atomic layer on Au is accompanied by spontaneous surface alloying and specific adsorption of anions.

Tuning the activity of Pt(111) for oxygen electroreduction by subsurface alloying.

To enable the development of low temperature fuel cells, significant improvements are required to the efficiency of the Pt electrocatalysts at the cathode, where oxygen reduction takes place. Herein, we study the effect of subsurface solute metals on the reactivity of Pt, using a Cu/Pt(111) near-surface alloy. Our investigations incorporate electrochemical measurements, ultrahigh vacuum experiments, and density functional theory.

The Pt(111)/electrolyte interface under oxygen reduction reaction conditions: an electrochemical impedance spectroscopy study.

The Pt(111)/electrolyte interface has been characterized during the oxygen reduction reaction (ORR) in 0.1 M HClO(4) using electrochemical impedance spectroscopy. The surface was studied within the potential region where adsorption of OH* and O* species occur without significant place exchange between the adsorbate and Pt surface atoms (0.

Screening of electrocatalytic materials for hydrogen evolution.

A general scheme for high-throughput screening of electrocatalysts is presented. By systematically exploiting a collection of theoretical and experimental materials databases, supplemented with quantum mechanical calculations, it locates systems that meet a set of pre-imposed selection criteria. As an example, the scheme is used to identify a binary "substrate-overlayer" electrocatalytic system for the hydrogen evolution reaction.