Glycerol Electro-Oxidation in Alkaline Medium with Pt-Fe/C Electrocatalysts Synthesized by the Polyol Method: Increased Selectivity and Activity Provided by Less Expensive Catalysts

Abstract

We have investigated platinum catalysts containing iron as a modifier to obtain catalysts with superior electrocatalytic activity toward glycerol electro-oxidation in an alkaline medium. The electrocatalysts, supported on carbon Vulcan, were synthesized by the polyol method. The physicochemical characterization data showed that the metals were well distributed on the carbon support and had small particle size (2 nm). The Pt:Fe metal ratio differed from the nominal composition, indicating that reducing iron with platinum was difficult, even though some parameters of the synthesis process were changed. Electrochemical analyses revealed that PtFe/C was more active and stable than commercial Pt/C was, and analysis of the electrolysis by-products showed that iron addition to Pt/C boosted the glycerol conversion and selectivity for glyceric acid formation.

Selective Glycerol‐to‐glycerate Electro‐oxidation on Cerium‐modified Pt/C Nanocatalyst in an Alkaline Direct Alcohol Fuel Cell: Cogeneration of Energy and Value‐added Products

“…The re‐oxidation peaks that emerged in the backward scan (cathodic path for both electrocatalysts) can be explained by restructuring/rearrangement of the surface oxides formed during the glycerol oxidation anodic sweep, making new active sites available. This important activity, albeit of lesser intensity, such that Pt and CeO 2 mutually aid each other by bifunctional catalysis, thanks to the formation/desorption of (hydro)oxide species [46,47] . The sharp peak at around 0.2 V vs Hg|HgO is included in the glycerol re‐oxidation region.…”

“…This important activity, albeit of lesser intensity, such that Pt and CeO 2 mutually aid each other by bifunctional catalysis, thanks to the formation/desorption of (hydro)oxide species. [46,47] The sharp peak at around 0.2 V vs Hg j HgO is included in the glycerol re-oxidation region. This peak, already obtained in the same potential range during ethanol oxidation on PtSnNi, [48] could be due either to the desorption of a species during the surface restructuring of the catalyst, or to the perturbation of the surface by the formation of oxygen bubbles on the co-catalyst sites, as CeO 2 acts as an oxygen pump.…”

Improved Glycerol Electrooxidation at Carbon-Supported PdFe Bimetallic Catalysts

“…6 In this sense, attention was drawn to alcohol oxidation-iron addition improved the reaction kinetics because it altered the palladium electronic structure and facets. [11][12][13] Glycerol is a byproduct (10% m/m) of biodiesel production. 40% of this byproduct is employed in the pharmaceutical industry.…”