Supporting electrolyte

About: Supporting electrolyte is a research topic. Over the lifetime, 5011 publications have been published within this topic receiving 104172 citations.

Graphene-supported [{Ru4O4(OH)2(H2O)4}(γ-SiW10O36)2]10− for highly efficient electrocatalytic water oxidation

Abstract: The electrochemistry of the Ru-containing polyoxometalate (POM) water oxidation molecular catalyst, Rb8K2[{Ru4O4(OH)2(H2O)4}(γ-SiW10O36)2]10− (Rb8K2-1), has been studied by cyclic and rotating disk electrode voltammetric methods in aqueous media under acidic and neutral pH conditions using bare glassy carbon (GC) and graphene modified GC electrodes. High concentrations of supporting electrolyte are needed in neutral pH conditions to overcome the electrical double layer effect associated with the highly negatively charged 1. Complex 1 can be confined within the highly porous wet graphene film to form a stable modified electrode, which shows excellent catalytic activity and high stability toward the water oxidation reaction under neutral pH conditions, particularly in the presence of 1.0 M Ca(NO3)2. The catalytic activity of the graphene supported 1electrode is nearly two orders of magnitude higher than that reported with a polymer coated multiwalled carbon nanotube supported 1electrode when both are employed at a moderate overpotential of 0.35 V.

Electrochemical oxidation of methanol on tin-modified platinum single-crystal surfaces

Abstract: To understand the role of tin as a promoter in the electrochemical oxidation of methanol, the authors have studied the geometric and electronic effect of tin atoms in different chemical states on/in the platinum surface by using single-crystal faces of the ordered alloy Pt{sub 3}Sn and single-crystal faces of pure Pt modified by electrodeposited/adsorbed tin, i.e., the so-called adatom state. They found that none of the alloy surfaces were more effective catalysts than any of the pure platinum surfaces under the conditions of measurement employed here and that alloying platinum with tin to any extent significantly reduced the activity. As reported previously by others, they observed tin to spontaneously adsorb on platinum surfaces from dilute sulfuric acid supporting electrolyte containing Sn(II) in concentrations above ca. 5 {mu}M. At a given concentration, the coverage by tin decreased as the atomic density of the platinum surface increased. However, they did not observe any enhancement of methanol oxidation on any platinum modified by this irreversibly adsorbed tin. They did observe a diffusion-limited enhancement on Pt(111) and on Pt(100) due to Sn(II) in the electrolyte at 1 {mu}M concentration. At this concentration, tin did not appear to be adsorbed to any observable extent, andmore » the catalysis appeared to occur via the direct interaction of a dissolved tin species with the surface. They propose a mechanism of catalysis that is a hybrid homogeneous-heterogeneous sequence based on known homogeneous Pt-Sn catalysts.« less

Bias-Switchable Permselectivity and Redox Catalytic Activity of a Ferrocene-Functionalized, Thin-Film Metal–Organic Framework Compound

Abstract: The installation of ferrocene molecules within the wide-channel metal–organic framework (MOF) compound, NU-1000, and subsequent configuration of the modified MOF as thin-film coatings on electrodes renders the MOF electroactive in the vicinity of the ferrocenium/ferrocene (Fc+/Fc) redox potential due to redox hopping between anchored Fc+/0 species. The observation of effective site-to-site redox hopping points to the potential usefulness of the installed species as a redox shuttle in photoelectrochemical or electrocatalytic systems. At low supporting electrolyte concentration, we observe bias-tunable ionic permselectivity; films are blocking toward solution cations when the MOF is in the ferrocenium form but permeable when in the ferrocene form. Additionally, with ferrocene-functionalized films, we observe that the MOF’s pyrene-based linkers, which are otherwise reversibly electroactive, are now redox-silent. Linker electroactivity is fully recovered, however, when the electrolyte concentration is increas...