Cavity microelectrodes for the voltammetric investigation of electrocatalysts: the electroreduction of volatile organic halides on micro-sized silver powders

Abstract

In this work the use of cavity-microelectrodes is described for the study of the electrocatalytic properties of silver powders in the electroreduction of trichloromethane, taken as model compound. The key role played by the Ag surface status has driven the research towards the use of micro-and nanosized materials, whose exploitation requires the full understanding of the complex behaviour of multiphasial interfaces, and the development of the appropriate investigation methodologies. Moreover, comparison with electrodeposited silver macroelectrodes demonstrates the advantages of using cavity-microelectrodes, especially in terms of improvement of the electrocatalytic activity, insignificance of ohmic drop and double layer capacitance in the voltammetric response, and simplicity offered by the experimental procedure for renovating the electrode material and surface.

Physico-chemical characterization of IrO2–SnO2 sol-gel nanopowders for electrochemical applications

“…CV and quasi steadystate voltammetric curves under OER conditions provide the electrochemical features of the mixed oxide, grown on Ti nets, unbiased by the contribution/cooperation of additives, implicit in gas diffusion electrodes (GDE) and membrane electrode assemblies (MEA). The consistency between the electrochemical response of the plain powder and the Ti-grown material was also confirmed by means of the cavity-microelectrode [32,33].…”

Rapid screening of silver nanoparticles for the catalytic degradation of chlorinated pollutants in water

“…On the other side, to correctly interpret the improved behavior of C1 and S1 at the most negative potentials, it should be taken into account that the electroreduction of organic polyhalides on an active surface is always a complex combination of phenomena that [32] (ii) the co-presence of adsorption-and diffusion-limited peaks [61]. In parallel, we could also propose a more rapid deactivation of C2 sites than S1 and C1.…”

“…Although most of the reported applications are performed on massive Ag electrodes, there are evidences [26,27,31,32] that micro and nanostructured particles exhibit a better performance than massive silver, allowing a substantial reduction of Ag loading.…”

Electroreductions on Silver‐Based Electrocatalysts: The Use of Ag Nanoparticles for CHCl3 to CH4 Conversion

“…Although most of the reported applications are performed on massive Ag electrodes, there is evidence [4,5] that microand nanostructured particles may exhibit similar or even better behaviour than massive silver, while allowing a substantial reduction of Ag loading. Moreover, as evidenced by [6] the Ag nanoparticle size deeply affects the dissociation of gaseous CHCl 3 on silver.…”

“…The Ag_NP/Carbon materials were characterised by X-ray powder diffraction analysis (XRPD). The composites were electrochemically characterised by means of the cavity micro-electrode (C-ME), a device especially developed for electrochemical studies of disperse systems [5,[35][36][37][38]. This allows a preliminary evaluation of their electrocatalytic activity and, accordingly, the ranking of the surfactants.…”