Enhanced electrooxidation of formic acid at Ta2O5-modified Pt electrode

Primary oxide (Pt-oH) latent storage induced spillover and reversible electrocatalysts for oxygen electrode reactions

“…Every cessation in the steam supply instantaneously imposes the sudden reversible shrinkage of both such rather exaggerated pairs of peaks down to the same initial potentiodynamic shape similar to the nanostructured Pt/C voltammogram spectra themselves. Vice versa, the renewed saturate water vapor feeding immediately leads to their former Pt-OH peaks and the same former charge capacities; namely, the effect already noticed and scanned for formaldehyde [28] and formic acid [29] oxidation. Such an appearance without exception behaves as a typical reversible transient phenomenon by its endless altering repetition, and never appears upon the plain Pt/C electrocatalyst, both wet and/or dry, nor with small and insufficient amounts of catalytic hypo-d-oxide supports.…”

“…1), as long as diffusional mass-transfer supply provides enough reacting species. Even more so, for interactive supported Pt and Au upon higher altervalent hypo-d-oxides and their mixed valence compounds, since these behave as highly enriched latent storage capacities of primary oxide spillover sources [16,17,28,29]. This is the cause and reason why within the reversible part of Tafel plots electrocatalytic metal (Pt,Au) surface is always covered by the interacting Pt-OH/Pt=O species, and naturally tends to impose the reversible oxygen electrode properties, and these are experimental evidence that the optimal catalytic rate implies their optimal ratio.…”

Poetics of Interplay and Interferences of Potentiodynamic Sweeps and Peaks in Electrocatalysis for Oxygen Electrode Reactions

“…In other words, the all parameters and conditions being kept the same, the reaction rate becomes dramatically different upon various supported electrocatalysts in their hypo-d-(f)-oxide amounts and/or exposure, as the result of distinctly different the additional Pt−OH spillover feeding and spreading effects, and as the only distinctly imposed difference. Such a conclusive observation belongs to the main experimental arguments to prove the theory of the M−OH interfering self-catalytic spillover contributions in electrocatalysis of aqueous media, (Equation 3), [6,7,41,42] finally providing the ROE behavior and properties, and traced the way and entire approach for its substantiation. In such a respect, cyclic voltammograms entirely deeper enlightened and more revealed the interfering spillover reaction impact properties of the Pt−OH.…”

“…[41]) and formic (muriatic) acid (Figure 3, Ref. [42]) anodic oxidation distinctly differ upon plain (Pt) or non-interactive carbon supported platinum (Pt/C), and the same, but more or less enriched and more exposed hypo-d-(f)-oxide support surfaces. Such a dependence, meanwhile, passes through certain maximum, since the increasing partial amount of hypo-d-(f)-oxides finally too much separates and isolates nanostructured Pt(Au) particles from each other.…”

“…Such a dependence, meanwhile, passes through certain maximum, since the increasing partial amount of hypo-d-(f)-oxides finally too much separates and isolates nanostructured Pt(Au) particles from each other. In such a context, at specific amounts of these interactive hypo-d-(Pt/Ta2O5/C, [41] and/or hypo-f-(Pt/CeO2/C [42] ) oxide supports, accounted per available metal electrode surface, the electrocatalytic activity increases remarkably, but not endlessly. In other words, the all parameters and conditions being kept the same, the reaction rate becomes dramatically different upon various supported electrocatalysts in their hypo-d-(f)-oxide amounts and/or exposure, as the result of distinctly different the additional Pt−OH spillover feeding and spreading effects, and as the only distinctly imposed difference.…”