Formic acid oxidation on Pd-modified Pt(100) and Pt(111) electrodes: A DEMS study

Abstract

Formic acid oxidation on palladium submonolayers on well-defined Pt(100) and Pt(111) electrodes has been studied using voltammetry and Differential Electrochemical Mass Spectrometry (DEMS). A combination of the two techniques allows a better understanding of the reaction taking place on the electrode surface. Thus, an exact correlation between the CO 2 mass signal and the current density in the voltammogram corresponding to the formic acid oxidation has been obtained. On palladium modified Pt(100) electrodes and in the potential region below 0.3 V, the currents in the positive scan are higher than those recorded in the negative scan. This diminution on the signal in the negative scan has been associated with CO 2 reduction to CO on the palladium adlayer. In addition, the CO 2 reduction reaction seems to take place on the border of the palladium islands. Finally, the adsorption of (bi)sulfate anions has an inhibiting behavior on the formic acid oxidation reaction.

Preferentially (100) oriented Pt thin film with less than a monolayer of Bi, Pd and Sb adatoms: application for formic acid oxidation

“…Fast poisoning was also observed on Pd ML-Pt (100) single crystals, and was attributed to the formation of blocking species on the Pd sites by a different mechanism than the one occurring on Pt [51]. The fact that sulfuric acid was used may also add some extra complications since a recent study suggested that the adsorption of (bi) sulfate anions has an inhibiting behavior on the formic acid oxidation reaction [52].…”

Formic acid electro-oxidation on carbon supported PdxPt1−x (0≥x≥1) nanoparticles synthesized via modified polyol method

“…Alloying of Pd with the second metal changes the surface electronic state, resulting in an ensemble effect, which can possibly reduce the catalyst poisoning and increase the activity and lifespan of the catalyst. A number of studies have been carried out recently with the aim to design multi-component Pd catalysts [22][23][24][25][26][27][28][29][30][31][32][33][34][35]. Approaches include the deposition of sub-monolayers of Pd on various supports, such as V, Mo, W and Au [26], Pt and Au single crystals [27][28][29][30][31].…”

“…A number of studies have been carried out recently with the aim to design multi-component Pd catalysts [22][23][24][25][26][27][28][29][30][31][32][33][34][35]. Approaches include the deposition of sub-monolayers of Pd on various supports, such as V, Mo, W and Au [26], Pt and Au single crystals [27][28][29][30][31]. Both Pd-Pt bulk and nano-catalysts [22][23][24][25][26][27][28][29][30][31][32][33][34][35] show high activity and improved stability in DFAFCs.…”

“…Approaches include the deposition of sub-monolayers of Pd on various supports, such as V, Mo, W and Au [26], Pt and Au single crystals [27][28][29][30][31]. Both Pd-Pt bulk and nano-catalysts [22][23][24][25][26][27][28][29][30][31][32][33][34][35] show high activity and improved stability in DFAFCs. For practical application, the Pd-Pt catalysts have to be prepared as highly dispersed, uniform nanoparticles.…”

Highly active carbon-supported PdNi catalyst for formic acid electrooxidation

“…Recently, the electrochemical oxidation of formic acid has been attracting increasing attention [1][2][3][4][5][6] because the direct formic acid fuel cell (DFAFC) has some advantages over the direct methanol fuel cell [7,8]. For example, formic acid is non-toxic and nonflammable.…”