Formic Acid Oxidation on Ultrathin Pd Films on Au(hkl) and Pt(hkl) Electrodes

Abstract

The oxidation of formic acid on thin, epitaxially-grown Pd overlayers on Au and Pt single crystal electrodes was studied as a function of overlayer thickness ranging from submonolayer coverages up to the equivalent of 10 monolayers. The results were compared with those for massive Pd single crystal surfaces. The electrocatalytic properties of the Pd overlayers were found to depend markedly on their thickness and on their crystallographic orientation. Pd(100) showed the highest catalytic activity of all three low-index faces, and Pd films on Pt(hkl), even when two or three layers thick, generally exhibited a much higher activity than Pd films on Au(hkl) or massive Pd(hkl). In all cases a high resistivity of the Pd surfaces against poisoning by CO was observed, which makes Pd an interesting alternative to the often quickly deactivated Pt as catalyst for organic fuel cell reactions.

Influence of thermal treatments on the stability of Pd nanoparticles supported on graphitised ordered mesoporous carbons

“…Kolb et al demonstrated that the electrocatalytic activity of Pd overlayers on Au and Pt single crystal electrodes depends markedly on their crystallographic orientation; following the trend Pd(111) < Pd(110) < Pd(100) [15,16]. Although in previous studies the same authors showed that the activity of Pd nanostructures towards HCOOH oxidation is enhanced in the presence of a carbon support, leading to lower deactivation kinetics under potentiostatic conditions [13,14,17];…”

Performance comparison of low-temperature direct alcohol fuel cells with different anode catalysts

“…Yet, it is still desirable to increase the number of liquid fuels that can be employed in these systems in order to extend the practical application of low-temperature fuel cells and to facilitate their penetration into energy market. Besides methanol, other small organic compounds such as formic acid [7][8][9][10][11], formaldehyde [9,11], ethanol [12], ethylene glycol [12,13], n-propanol [12] and so on have been investigated and demonstrated appropriate for this type fuel cell, because they are reasonably inexpensive, nontoxic and largely available and have suitable electrochemical reactivity at relatively low temperatures. Furthermore, they have comparable energy density and reversible energy efficiency compared to H 2 .…”

CO adsorption and kinetics on well-characterized Pd films on Pt() in alkaline solutions

“…Only shortly after the successful UHV studies, the adsorption and catalytic properties of pseudomorphic Pd films supported on single crystal metal surfaces has also received considerable attention in the field of surface electrochemistry [10][11][12][13][14][15][16][17][18][19][20][21].…”