Electrochemical Reactivity of Aromatic Molecules at Nanometer-Sized Surface Domains: From Pt(hkl) Single Crystal Electrodes to Preferentially Oriented Platinum Nanoparticles

Abstract

This manuscript compares the electrochemically controlled adsorption of hydroquinone-derived adlayers and their reductive desorption from nanometer-sized Pt(111) domains present on the surface (i) of model stepped single-crystal electrodes and (ii) of preferentially oriented Pt nanoparticles. The results obtained using a stepped surface series, i.e., Pt(S)[(n - 1)(111)x(110)], suggest that in the presence of 2 mM H(2)Q((aq)) the electrochemically detected desorption-adsorption process takes place selectively from ordered Pt(111) domains present as terraces, while being precluded at other available surface sites, i.e., Pt(110) steps, where adsorption takes place irreversibly. This domain-selective electroanalytical detection scheme is employed later to selectively monitor desorption-adsorption of hydroquinone-derived adlayers from ordered, nanometer-scaled Pt(111) domains on the surface of preferentially oriented Pt nanoparticles, confirming the existence of well-ordered (111) domains on the surface of the Pt nanoparticles. A good correlation is noted between the electrochemical behavior at well-ordered Pt(hkl) surfaces and at preferentially oriented Pt nanoparticles. Key learnings and potential applications are discussed. The results demonstrate the technical feasibility of performing domain-selective decapping of nanoparticles by handle of an externally controlled parameter, i.e., the applied potential.

Electrochemical Characterization of Clean Shape‐Controlled Pt Nanoparticles Prepared in Presence of Oleylamine/Oleic Acid

“…[19] As described in previous contributions, this process was reported to take place selectively from ordered Pt(111) domains present as terraces, being precluded at other available surface sites. Figure 10 reports the voltammetric profiles for both reactions for some of representative Pt nanoparticles.…”

Synthesis and characterization of polyhedral Pt nanoparticles: Their catalytic property, surface attachment, self-aggregation and assembly

“…The PtO formation was observed at potentials higher than 0.5 V in the forward sweep. The reduction in PtO formation was exhibited by the negative peak in the reverse scan at 0.5 V. In addition, a reduction current in potential window from À0.60 to 0.15 V can be attributed to a long-range adsorption state at {1 0 0} terraces [55]. The relative peak height in respective to the two aforementioned Pt sites can give the meaningful insights into the polyhedral shape and yield of Pt nanoparticles [21].…”

Size-Dependent Underpotential Deposition of Copper on Palladium Nanoparticles

“…[26][27][28] However, a more noble metal shell cannot be deposited by UPD. This can be solved by using a galvanic replacement technique.…”