Peroxodisulfate reduction on platinum stepped surfaces vicinal to the (110) and (100) poles

Abstract

Peroxodisulfate reduction on platinum stepped surfaces vicinal to the ( 110) and (100) poles,

Nitrate anion reduction in aqueous perchloric acid as an electrochemical probe of Pt{1 1 0}-(1 × 1) terrace sites

“…It should be noted that in the present study, the whole of the reduction current has been assigned to nitrate reduction rather than NO(ad) which is also redox active in this potential range [57]. Although we have not explicitly investigated the mechanism of nitrate reduction in this study, two issues indicate to us that nitrate reduction belongs to a class of redox reaction which also includes nitrous oxide reduction, persulphate reduction and nitrite reduction, that reflect i) a weakly adsorbed reactant relative to other double layer species (hydrogen underpotential deposition (Hupd) species / anion adsorption / water dipoles) and ii) also give rise to a peak maxima close to the local pzc of the electrode surface [57][58][59][60][61][62]. In this way, the decomposition mechanism of nitrate is assumed to follow closely that which was outlined previously by Attard and coworkers in the case of nitrous oxide reduction [63] and indeed Koper et al for nitrate reduction [12].…”

New insights into the Pt(hkl)-alkaline solution interphases from the laser induced temperature jump method

“…On one side, the sensitivity of some reactions to the electrode charge has been exploited to gain further information about the interphase. N 2 O [17][18][19] and peroxodisulfate reductions [10,[20][21][22][23] have been successfully used with this purpose. In electrocatalysis, H 2 O 2 and O 2 [24] reduction have been also shown to be sensitive to the interfacial charge.…”

Double-Layer Inhibition of Peroxydisulfate Reduction at Mercury Ultramicroelectrodes. A Quantitative Analysis of the Frumkin Effect Including Molecular Transport and Long-Range Electron Transfer

“…cannot be excluded, as discussed in the literature. 11,12,15 While a precise molecularly resolved description of the electrode/ solution interface is not experimentally obtainable, adsorption can be approximated as treating the plane of closest approach for S 2 O 8 2− as the IHP, as shown in Figure 2. Long-range electron tunneling to S 2 O 8 2− beyond the IHP may occur analogous to Ru(NH 3 ) 6 3+ , with a predicted exponential decay in electron transfer rate as a function of S 2 O 8 2− /electrode separation.…”

“…The electric double layer (EDL) at the electrode/solution interface can significantly affect the adsorption of molecules and ions, and the energetics and rates of electrochemical reactions. − A classic example of a double layer effect observed in voltammetric experiments involves the reduction of peroxydisulfate (S 2 O 8 2– ). − The redox mechanism involves an initial electron transfer to S 2 O 8 2– to form the corresponding radical anion, S 2 O 8 3–• , which rapidly dissociates to SO 4 2– and SO 4 –• . The strongly oxidizing SO 4 –• is then reduced in a second redox step (see Supporting Information for analysis and discussion of E 0 values; all reported potentials herein are relative to Ag/AgCl (3 M KCl)). S 2 normalO 8 2 − + e − ⇄ S 2 normalO 8 3 − • ⁣ E 0 = 0.33 V false( normalvs . .25em normalAg / normalAgCl false) S 2 normalO 8 3 − • ⇄ normalSO 4 2 − + normalSO 4 − • …”