Construction of multilayers of bare and Pd modified gold nanoclusters and their electrocatalytic properties for oxygen reduction

Abstract

Multilayers of gold nanoclusters (GNCs) coated with a thin Pd layer were constructed using GNCs modified with self-assembled monolayers (SAMs) of mercaptoundecanoic acid and a polyallylamine hydrochloride (PAH) multilayer assembly, which has been reported to act as a three-dimensional electrode. SAMs were removed from GNCs by electrochemical anodic decomposition and then a small amount of Pd was electrochemically deposited on the GNCs. The kinetics of the oxygen reduction reaction (ORR) on the Pd modified GNC/PAH multilayer assembly was studied using a rotating disk electrode, and a significant increase in the ORR rate was observed after Pd deposition. Electrocatalytic activities in alkaline and acidic solutions were compared both for the GNC multilayer electrode and Pd modified GNC electrode.

Examination of the electroactive composites containing cobalt nanoclusters and nitrogen-doped nanostructured carbon as electrocatalysts for oxygen reduction reaction

“…The kinetic current (i k ) of ORR can be obtained from the intercept of the K.eL. plots for various potentials and then the kinetic rate constant (k) of ORR (shown in Table 4) is obtained by the following equation [63]: Fig. 12 shows Tafel plots of mass-transport-corrected currents at GC electrode coated with the composites.…”

N- and S-doped high surface area carbon derived from soya chunks as scalable and efficient electrocatalysts for oxygen reduction

“…Although the performance of a polymer electrolyte membrane fuel cell (PEMFC) has improved in recent times, it is of paramount importance to develop better catalysts to counter the sluggish kinetics of an oxygen reduction reaction at the cathode [ 1 ]. Usually, noble-metal-based electrocatalysts are considered to be the best catalyst for an oxygen reduction reaction (ORR) in fuel cells [ 2 – 5 ]. However, high cost and lack of abundance limit their utilization [ 6 ].…”

Size dependent lattice constant change of thiol self-assembled monolayer modified Au nanoclusters studied by grazing incidence x-ray diffraction

“…Multilayers of GNCs were prepared on a commercially available Au(111) substrate, which was annealed and quenched prior to use, by repeating the two-step dip and rinse cycles for 10 times based on the carboxylate/poly(allylamine hydrochloride) (PAH)/carboxylate electrostatic interaction [16][17][18][19][21][22][23]. Cyclic voltammograms (CVs) of the Au(111) electrode modified with these mixed SAM modified GNCs multilayers were measured in a deaerated 0.1 M HClO 4 solution at a scan rate of 50 mV s -1 in the potential range between 0 and 1.30 V with respect to the Ag/AgCl electrode.…”

“…Previously, we succeeded [16][17][18][19][20][21][22][23][24] to synthesize gold nanoclusters (GNCs), of which surface was covered with the mixed self-assembled monolayers (SAMs) of mercaptoundecanoic acid (MUA), 3 hexanethiol (C 6 SH), and ferrocenylhexanethiol (FcC 6 SH), using the methods by Brust et al [25] and Hostetler et al [26] and to construct the multilayers of GNCs on the solid surface, using the cation/anion electrostatic interaction [27][28][29][30][31]. When the potential was made more positive than that for the oxidative decomposition of the thiol SAM on gold [32][33][34][35], the SAM was gradually removed from the GNCs and GNCs started to aggregate [22,23].…”

“…When the potential was made more positive than that for the oxidative decomposition of the thiol SAM on gold [32][33][34][35], the SAM was gradually removed from the GNCs and GNCs started to aggregate [22,23].…”