Electrocatalytic Reduction of Oxygen on a Pd Ad-Layer Modified Au(111) Electrode in Alkaline Solution

Abstract

Oxygen reduction was studied on palladium, cadmium and zinc ad-atom modified single crystal Au (111) electrodes. The electrodes were modified by underpotential deposition process and their activity towards oxygen reduction was studied in alkaline media by voltammetry. The reduction peaks obtained were compared with those of bare Au (111), Pd disc and bulk deposited Cd electrodes. Enhanced catalytic activity of the Au(111) electrode in the presence of Pd, Cd and Zn ad-layer can be attributed to a change in surface charge and energy by ad-layer formation. In oxygen saturated medium a well defined sharp reduction peak was observed at -0.12 V for 1/5 ML Pd ad atom modified Au(111) electrode while it was positioned at -0.18 V on a Pd disk electrode. The best shift in reduction peak potential was obtained with 2/5 ML Pd ad atom modified Au(111) electrode with similar current density of Pd disc electrode.

Electrocatalytic reduction of oxygen on bimetallic copper–gold nanoparticles–multiwalled carbon nanotube modified glassy carbon electrode in alkaline solution

“…Two Tafel slope regions could be attributed to the change from Temkin to Langmiur conditions for changing coverage of surface by adsorbed oxygen species. These slopes were found very similar to Pd ad-layer modified Au(1 1 1) [9] and Pt ad-layer modified Au(1 1 1) [47], nanostructure gold electrode [48]. At low current regions, Tafel slopes were indicated a stage of first electron transfer step being the rate determining step for oxygen reduction at MWCNT/GCE, Cu-MWCNT/GCE, Au-MWCNT/GCE and Cu (4cyc) -Au (6cyc) -MWCNT/GCE.…”

“…Therefore, recently, various new types of cathode catalysts, such as single crystals of noble metals [6,7], single crystals modified with different metal ad-layers [8,9], Pt-free catalysts [10,11] and Pt-based metal alloys [12,13] have been applied for electrocatalytic reduction of oxygen.…”

Probing the Surface of Noble Metals Electrochemically by Underpotential Deposition of Transition Metals

“…Therefore, upd of a metal monolayer onto polycrystalline or single-crystal substrates of a foreign metal has been studied intensively. These investigations included various substrates such as Au, Pt, Ag, Cu, Rh, Ru, Pd, and many deposited ions like Ag + [13,14], Cu 2+ [15][16][17][18][19][20][21][22][23][24], Cd 2+ [25], Pb 2+ [26][27][28][29][30], Tl + [31][32][33][34], Cd 2+ [35,36], Hg 2+ [37], Sn 2+ [38,39], Bi 3+ [30,[40][41][42][43][44][45], Ge 4+ [46][47][48], Sb 2+ [49][50][51], and Ni 2+ [52]. The charge corresponding to the upd permits researchers to estimate the amount of deposited metal.…”

Polymer Film Supported Bimetallic Au–Ag Catalysts for Electrocatalytic Oxidation of Ammonia Borane in Alkaline Media

“…Bimetallic nanoparticle-modified electrodes have been studied extensively due to their improved catalytic performance owing to their synergistic and electronic effects [ 33 – 37 ]. Synthesis of bimetallic particles can be carried out through various methods, such as electroless plating [ 37 ], surface reaction [ 38 ], seeding-mediated synthesis [ 39 ], self-assembly, and electrochemical methods [ 40 , 41 ]. Among them, electrochemical synthesis is an easy approach in preparing bimetallic surfaces by controlling the impurities, particle sizes, and the amount of modifier components.…”