Electroreduction of oxygen on carbon-supported gold catalysts

Shape‐Dependent Electrocatalysis: Oxygen Reduction on Carbon‐Supported Gold Nanoparticles

“…Similarly, more-negative slope values have been previously observed for some Au single-crystal electrodes [21,22] and Au/ C catalysts. [47] In addition, morenegative Tafel slope values due to the porosity of the catalyst have been obtained in case of thick catalyst layers, [77] however, in this work the catalyst loading was much lower and presumably the reaction was not limited by thin-layer diffusion, as confirmed for Au/C catalysts of various loadings. [47] Therefore, the precise reason for the higher value of slope is not clear at present, but it is expected to be related to the reaction kinetics and not to diffusion effects.…”

“…[42,[44][45][46] Previously, we have also studied the effect of Au/ C layer thickness on the electrocatalytic activity for ORRs in acidic and alkaline solutions and found that the SA of Au is independent of catalyst loading. [47] AuNPs in conjunction with organic compounds have also shown high activity for O 2 reduction. [58,59] Experiments with Nafion-coated bulk Au electrodes showed no clear evidence of the enhancement effects of Nafion coatings on the cathodic O 2 reduction.…”

“…Thus, AuNPs supported on high-area carbon materials such as carbon nanotubes or carbon black and, more recently, on graphene, have been used as electrocatalysts for O 2 reduction. [41][42][43][44][45][46][47][48][49][50][51][52][53][54] Tang et al investigated how Au particle size affects the ORR activity in a basic electrolyte. [41] They found that 3 nm Au clusters on a carbon support exhibited higher ORR activity, and also a four-electron reduction of O 2 occurred on these particles, whereas on 7 nm AuNPs the two-electron reduction to HO 2 À predominates.…”

Electrocatalytic Activity for Oxygen Reduction Reaction of Au Core/Pt Shell Nanoparticle-Loaded Carbon Black Catalyst with Different Core Sizes

“…The CVs of each electrode in Ar-saturated 0.1 M HClO 4 aqueous solution were measured between 0.05 and 1.7 V at a sweep rate of 20 mV s À1 . The electrochemical surface area (ECSA) of Au (ECSA Au ) was evaluated by dividing the quantity of electricity required to completely reduce the Au oxide layer by 400 mC cm À2 , which is the quantity of electricity required per unit area for polycrystalline Au [21,22]. The ECSA of Pt (ECSA Pt ) was determined by dividing the electric charge for hydrogen desorption evaluated from the positive CV at 20 mV s À1 by that of smooth polycrystalline Pt (210 mC cm À2 ) [23].…”

Trends in the Electrochemical Synthesis of H2O2: Enhancing Activity and Selectivity by Electrocatalytic Site Engineering

“…Notably, pure Ag has a high activity for this reaction, similar to that of Pt−Hg. All these materials are more active than Aubased catalysts, which have been extensively investigated in previous studies; 7,28,29 Pt−Hg, Ag, and Ag−Hg exhibit an order of magnitude improvement over Au, whereas the activity of Pd−Hg is 2 orders of magnitude higher.…”