Oxygen electroreduction on carbon-supported Pd nanocubes in acid solutions

Abstract

Please cite this article as: Heiki Erikson, Madis Lüsi, Ave Sarapuu, Kaido Tammeveski, Jose Solla-Gullón, Juan M.Feliu, Oxygen electroreduction on carbon-supported Pd nanocubes in acid solutions, Electrochimica Acta http://dx.doi.org/10.1016/j.electacta. 2015.11.125 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Oxygen electroreduction on carbon-supported Pd nanocubes in acid solutions Highlights• Carbon-supported Pd nanocubes of three different size and loading were prepared• The specific activity for oxygen reduction reaction is independent of Pd content• Pd nanocubes possess higher specific activity for ORR than spherical Pd nanoparticles• The ORR on carbon-supported Pd nanocubes proceed mainly via 4-electron pathway• Tafel behaviour of ORR on carbon-supported Pd nanocubes is similar to that of bulk Pd AbstractThe oxygen reduction reaction (ORR) was studied on carbon-supported cubic palladium nanoparticles of different sizes (~30 nm, ~10 nm and ~7 nm). Cetyltrimethylammonium bromide (CTAB) and polyvinylpyrrolidone (PVP) were used as capping agents to prepare the nanocubes and Pd content in the catalyst samples was 20 and 50 wt%. The surface morphology of the prepared materials was studied by transmission electron microscopy (TEM). The catalyst materials were electrochemically characterised by cyclic voltammetry and CO stripping experiments. The rotating disk electrode (RDE) method was employed for ORR studies in 0.5 M H 2 SO 4 and 0.1 M HClO 4 solutions. The ORR results revealed that the specific activity of cubic Pd nanoparticles is higher than that of spherical Pd particles and does not depend on the Pd content in the catalyst, but decreases with decreasing the size of Pd nanocubes. Mass activity of Pd nanocubes increased with decreasing the particle size. The ORR proceeds mainly via 4-electron pathway and the reaction mechanism is similar to that on bulk Pd.

Ultrasmall Palladium Nanoclusters as Effective Catalyst for Oxygen Reduction Reaction

“…[23] Thes uccess in thes ynthesis of gold nanoclusters broughtu p theq uestion of whethero ne cana pply thes ynthetic methods to otherm etalsa nd expand thef amily of ultrasmallm etal clusters.Palladium-based nanomaterialshavereceivedincreasingattentioni nt he search forn on-platinum catalystst owards the oxygen reductionreaction(ORR),owing to thes carcityand high cost of platinum.A mongt he alternativem etals, Pd hasb een considered as ap romisingc andidate with satisfactory electrocatalyticp erformance andalowerc ost. [24,25] VariousP d-based nanomaterialsh aveb eenr eporteda se ffective electrocatalysts fort he ORR, such as nanorods, [26] nanocubes, [27][28][29][30][31] nanoflowers, [32] five-foldt winned nanocrystals, [33] andc ore-shelln anostructures. [34][35][36][37][38] As an emerging type of nanostructure, ultrasmall palladiumn anoclustersa re highly desirable, buth aven ot been paid sufficient attentiont o, owingp artlyt od ifficultiesi nt he controlled synthesis.…”

Electroreduction of Oxygen on Carbide‐Derived Carbon Supported Pd Catalysts

“…The Tafel slope values were calculated at low current densities, with all catalysts showing a slope slightly higher than −60 mV. This slope value corresponds to the oxide covered Pd catalysts . Higher Tafel slope values than −60 mV have also been observed in the literature and these are usually attributed to the influence of a carbon support .…”

Oxygen reduction reaction on carbon-supported palladium nanocubes in alkaline media

“…potentiostat/galvanostat (Metrohm Autolab). The experiments of CO stripping, cyclic voltammetry (CV) and oxygen reduction were carried out similarly to previous publications [9,10,17]. The experiments were repeated five times for better evaluation of the catalysts.…”

“…In acid media the carbon-supported Pd nanocubes had higher specific activity than spherical Pd nanoparticles and commercial Pd/C catalyst [17] and therefore the purpose of the present research was to compare the ORR activity trends in 0.1 M KOH.…”