Pt₅Gd as a Highly Active and Stable Catalyst for Oxygen Electroreduction

Abstract

The activity and stability of Pt(5)Gd for the oxygen reduction reaction (ORR) have been studied, using a combination of electrochemical measurements, angle-resolved X-ray photoelectron spectroscopy (AR-XPS), and density functional theory calculations. Sputter-cleaned, polycrystalline Pt(5)Gd shows a 5-fold increase in ORR activity, relative to pure Pt at 0.9 V, approaching the most active in the literature for catalysts prepared in this way. AR-XPS profiles after electrochemical measurements in 0.1 M HClO(4) show the formation of a thick Pt overlayer on the bulk Pt(5)Gd, and the enhanced ORR activity can be explained by means of compressive strain effects. Furthermore, these novel bimetallic electrocatalysts are highly stable, which, in combination with their enhanced activity, makes them very promising for the development of new cathode catalysts for fuel cells.

Exploring the phase space of time of flight mass selected PtxY nanoparticles

“…[39][40][41] In our laboratory we have taken a different approach, namely to study alloys of Pt and rare earths such as Y, Gd, Ce and La. 33,[42][43][44][45][46][47][48] These alloys have a particularly negative heat of formation, which should provide them with long term-kinetic stability against dealloying at the cathode of a fuel cell. Extended surfaces of Pt 3 Y and Pt 5 Gd show particularly high activity for oxygen reduction.…”

“…Extended surfaces of Pt 3 Y and Pt 5 Gd show particularly high activity for oxygen reduction. 42,43,47 On the other hand, upon exposure to reaction conditions, alloys such as Pt 2 Y or PtY corroded extensively, due to Y dissolution; this suggests that an excessive amount of Y is detrimental to catalyst stability. 44 Most recently, we demonstrated that Pt x Y is also highly active for the oxygen reduction reaction in nanoparticulate form.…”

Electrochemical preparation and characterization of PdPt nanocages with improved electrocatalytic activity toward oxygen reduction reaction

“…The development of nanostructured Ptbased electrocatalysts is considered to be one of the most effective approaches to resolve these problems [3]. In the sight of composition, Pt based alloys are believed to improve the ORR activity [4][5][6][7][8], because the introduction of other metal compositions modifies the electronic and crystallographic structures of Pt, resulting in the decrease of the binding energy between Pt and oxygen [9]. On the other hand, the shape and morphology of nanocrystals are also of great importance in the development of ORR catalysts.…”

What Can We Learn in Electrocatalysis, from Nanoparticulated Precious and/or Non-Precious Catalytic Centers Interacting with Their Support?

“…Pt-M nanoalloys supported by carbon black were developed to investigate the dealloying effect of M atoms on Pt surface towards ORR activity in acid medium [215,219]. Recently, supported by theoretical DFT (density functional theory) calculation, Chorkendorff's group reported experimental facts showing that the Pt-RE (RE = rare earth elements) alloys were the most active and stable Pt-based electrocatalysts for ORR [12,[222][223][224]. Therefore, the synthesis of highly and homogeneously dispersed Pt-RE nanoalloys is an interesting phenomenon in the domain of energy conversion.…”