Hydrogen-assisted and CO-assisted reductive desorption of hydroquinone-derived adlayers from Pt(111) single crystal electrodes

Selective deposition of Pt onto supported metal clusters for fuel cell electrocatalysts

“…Attractive interactions in the HQ-derived adlayer have also been reported. 40,41,42 The narrow width of the redox peak on Pt might be attributed to the formation of a compact arrangement of molecules in the adlayer.…”

Use of Model Pt(111) Single Crystal Electrodes under HMRDE Configuration To Study the Redox Mechanism for Charge Injection at Aromatic/Metal Interfaces

“…In ESS well-ordered Pt( hkl ) single crystal electrodes, prepared by the methods pioneered by Clavilier, have been broadly adopted as model systems to elucidate the controlling role played by surface structure and composition over electrochemical reactivity. Studies of aniline, benzene (C 6 H 6 ), parabanic acid, hydroquinone ( p -H 2 Q) , and catechol ( o -H 2 Q) adsorption have been reported at bead-type Pt(111) single-crystal electrode surfaces. The spontaneous formation of compact adlayers derived, in acidic aqueous media, from such molecules have been reported.…”

“…The aim of the comparison is to elucidate (i) if molecular desorption takes place during the CV excursions, hence permitting H UPD adsorption at Pt(111) surface atoms as proposed by Itaya et al; or (ii) if, instead, aromatic molecules remain chemisorbed during electrode polarization, hence bringing about the new physicochemical properties postulated to exist by Jerkiewicz et al at the noble metal/aromatic surface and/or subsurface. The hydroquinone and catechol molecule were selected for comparison purposes because their spectroelectrochemical reactivity at well-ordered Pt(111) electrodes has been studied and reported, , thus serving as model, electrochemically active, aromatic molecular probes. For the three adlayers studied, the results demonstrate that reductive desorption of the molecules is accomplished within the time frame of the first cathodic scan, i.e.…”

Size-Dependent and Step-Modulated Supramolecular Electrochemical Properties of Catechol-Derived Adlayers at Pt(hkl) Surfaces

“…p- H 2 Q denotes the para -substitution of the benzene ring in the 1,4-benzenediol molecule. In ESS studies, quinoidal molecules have also served as prototypical redox-active, aromatic chemisorbates. − ,− During the early development of ESS as a field of study, one of the first reports of molecular self-assembly dealt with the molecular adsorption of p-hydroquinone monolayers at Pt electrode surfaces . Few molecular ESS probes have been studied in such detail.…”

“…Few molecular ESS probes have been studied in such detail. Recently, a surface-selective redox process (eq ) has been reported for p- H 2 Q in aqueous sulphuric media: − normalQ false( ads false) Pt ( 111 ) + ( z + 2 ) e − + ( z + 2 ) normalH + ↔ Pt ( 111 ) z normalH false( ads false) Pt ( 111 ) + normalH 2 normalQ false( aq false) where z represents the number of protons reduced to adsorbed hydrogen adatoms (H ads ) at well-ordered Pt(111) surface domains, when an adsorbed quinone molecule, Q (ads), is reduced to H 2 Q (aq) . The high surface specificity and selectivity of the redox process, occurring only at well-ordered Pt(111) domains, was recently employed analytically to quantify (111) terraces at model Pt( hkl ) stepped surfaces and to confirm the presence of ordered (111) facets at preferentially oriented Pt nanoparticles using cyclic voltammetry (CV).…”