Glycerol Electrooxidation on Well-Shaped Pd Nanoparticles Modified By Bi-Adatoms

The electrochemical conversion of glycerol gains more and more attention because glycerol is a by-product of biofuel industries, and for its potency for electric energy or hydrogen and added-value-chemical cogeneration [1]. Due to complex oxidation pathways a large number of useful chemicals may be produced [2]. The control of activity and selectivity can be provided by the electrode potential and the formulation of electrocatalysts. In alkaline medium, palladium is a catalytic metal active for the electrooxidation of small organic molecules [3–5]. Many electrocatalytic reactions on Pd surface are known to be structure sensitive [6,7]. The activity and selectivity of Pd catalysts can also be tuned by modification with p-group atoms, such as Bi [8,9]. Moreover, it has been proposed that the structure of the electrodes (unsupported, self-supported or carbon supported Pd-Bi catalysts) has an important effect on the electrocatalytic behavior, influencing the activity as well as the selectivity of the reaction.

Here, the synthesis of preferentially-shaped Pd nanoparticles, their physico-chemical characterization and their surface modification by spontaneous bismuth adsorption are described, as well as their activity towards glycerol electro-oxidation.

In order to better, understand the role of palladium surface and bismuth modification on polyol oxidation, electrochemical measurements have been carried out on palladium nanocubes and nanooctahedrons with high amount of {100} and {111} surface nanodomains, respectively, and nanospheres without preferential surface orientation. Glycerol electrooxidation has been studied and compared on both nanoparticles, before and after modification by Bi adatoms; in situ infrared spectroscopy measurements of glycerol electrooxidation on Bi-modified Pd surfaces were also performed to determine adsorbed intermediates and reaction products versus Bi surface coverage.

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