Catalysts for oxygen reduction reaction based on nanocrystals of a Pt or Pt–Pd alloy shell supported on a Au core

Venarusso, Luna B.; Bettini, Jefferson

doi:10.1007/s10008-016-3181-z

Cited by 20 publications

(13 citation statements)

References 60 publications

(53 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The XRD patterns for the non‐electrochemically stabilized Pt−Pd/GNR and Ti/Pt−Pd/GNR nanocomposites (Figure S6A) show the features of face‐centered cubic crystalline characteristic peaks of Pt−Pd alloy (1 1 1), (2 0 0), (2 2 0), (3 1 1), and (2 2 2), with the planes at 2 θ =40.0°, 46.8°, 68.0°, 82°, and 86.6°, respectively, as well as the presence of a small broad peak at 2 θ =25.9° corresponding to the graphitic state plane (0 0 2) of GNR for the non‐electrochemically stabilized Pt−Pd/GNR nanocomposite. The last peak appears as an increased broad peak at 2 θ =25.6° corresponding to the TiO 2 state plane (1 0 1), and which is related to the non‐electrochemically stabilized Ti/Pt−Pd/GNR nanocomposite.…”

Section: Resultsmentioning

confidence: 95%

See 1 more Smart Citation

Ti/Pt−Pd‐Based Nanocomposite: Effects of Metal Oxides on the Oxygen Reduction Reaction

2020

Self Cite

View full text Add to dashboard Cite

Over the last few years, there has been an intensive search for stable and highly active electrocatalysts, which are intended to be applied in oxygen reduction reaction (ORR) preferably without the use of noble metals or with the application of a very small quantity of these metals in the process. Electrocatalysts that satisfy these conditions can be composed of Ti and other metals, supported or not by carbonaceous materials. The present work reports the application of synthesized threedimensional Ti/PtÀ Pd nanoparticles with highly rough surfaces supported on graphene nanoribbons (Ti/PtÀ Pd/GNR nanocomposite) by a single one-pot reaction, and applied in ORR. Unlike the effect of strong metal-support interaction (SMSI), which favors electrons transfer from the metal support to the catalyst, the mechanism employed in this study favored the transfer of electrons from the catalyst to the metal support; in other words, the mechanism led to the oxidation of Pt and Pd. Pt, which exhibited PtÀ Pd type alloy features, was found to be more externally distributed at the rough surface of the metallic structures. Additionally, Ti, which presented oxide features, was found to be even more externally distributed at the surface of PtÀ Pd on non-electrochemically and electrochemically stabilized Ti/PtÀ Pd/GNR nanocomposite electrodes. Since all these metals have great amounts of different oxides (i. e. are highly oxidized), the oxides are found to be energetically responsible for the improvement in ORR electrocatalytic activity and stability of Ti/PtÀ Pd/GNR/GC electrodes in comparison with the ORR responses for PtC TKK/GC and PtÀ Pd/GNR/GC modified electrodes. To Ti-containing catalysts, the high activity is attributable to enhancing the intrinsic activity and the high selectivity to 4-electron ORR is due to the fact that presence of Ti contributes to oxygen-binding energy of these nanocomposites shifts toward more positive values (weakening oxygen bonding).[a] G.

show abstract

Section: Resultsmentioning

confidence: 95%

“…Visible metallic structures with highly rough surface can be observed on GNR (Figures , S1, and S2) with PSD of 12.8±3.4 nm on average (c.f. Figures and S2).…”

Section: Resultsmentioning

confidence: 99%

Ti/Pt−Pd‐Based Nanocomposite: Effects of Metal Oxides on the Oxygen Reduction Reaction

2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…34,37 However, experimental studies have successfully demonstrated the formation of particles with a Pt-rich shell on an alloyed Au-containing core. [50][51][52][53][54][55][56][57][58] Adsorbate induced stabilisation has also been suggested to play a role in formation of Pt over an Au-containing core under ORR conditions. Oxygen and hydroxyl bond more strongly to Pt than to Au, thus when metastable structures are formed, the presence of an oxygen atmosphere stabilises this structure with a Pt-shell.…”

Section: Introductionmentioning

confidence: 99%

Decoupling strain and ligand effects in ternary nanoparticles for improved ORR electrocatalysis

Jennings

Lysgaard

Hansen

et al. 2016

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

Ternary Pt-Au-M (M = 3d transition metal) nanoparticles show reduced OH adsorption energies and improved activity for the oxygen reduction reaction (ORR) compared to pure Pt nanoparticles, as obtained by density functional theory. The strain and ligand effects in nanoparticles are decoupled and correlated with the extended Pt(111) surface for benchmarking. The ternary metal in the core allows for tuning the catalytic activity through strain effects. Pt-Au-M for M = Cr, Mn, Co, Cu, Zn nanoparticles are of particular interest as they exhibit an optimal contribution of strain, ligand effects and stability. Good agreement is found with experimental studies showing increased activity of Pt-Au-Fe/Ni nanoparticles, and mid to late 3d transition metals are predicted to exhibit enhance activity and stability with respect to pure Pt nanoparticles.

show abstract

“…A secondary reaction can occur, which is the 2e-reduction of oxygen to hydrogen peroxide, known as the "peroxide route" [5]. Although innumerable experimental studies have been carried out on noble [6,7,8,9] and non-noble [10,11,12] metals, alloys [13,14,15,16], etc., unfortunately, they do not give a consistent picture of the reaction mechanism and their results are still under debate [5,17]. In principle, considering the simultaneous occurrence of both routes, the mechanism of the orr in acid media could proceed through different adsorbed intermediates on active sites on the metal electrode which determine the final products, H 2 O and/or H 2 O 2 .…”

Section: Introductionmentioning

confidence: 99%

Oxygen reduction reaction (orr) on bimetallic AuPt and AuPd(1 0 0)–electrodes: Effects of the heteroatomic junction on the reaction paths

Schulte

Belletti

Arce

et al. 2018

Applied Surface Science

View full text Add to dashboard Cite

The seek for materials to enhance the oxygen reduction reaction (orr) rate is a highly relevant topic due to its implication in fuel cell devices. Herein, the orr on bimetallic electrocatalysts based on Au-M (M= Pt, Pd) has been studied computationally, by performing density functional theory calculations. Bimetallic (100) electrode surfaces with two different Au:M ratios were proposed, and two possible pathways, associative and dissociative, were considered for the orr. Changes in the electronic properties of these materials with respect to the pure metals were acknowledged to gain understanding in the overall reactivity trend. The effect of the bimetallic junction on the stability of the intermediates O2 and OOH was also evaluated by means of geometrical and energetic parameters; being the intermediates preferably adsorbed on Pt/Pd atoms, but presenting in some cases higher adsorption energies compared with bare metals. Finally, the kinetics of the O-O bond breaking in O * 2 and OOH * adsorbed intermediates in the bimetallic materials and the influence of the Au-M junction were studied by means of the nudge elastic-band method. A barrierless process for the scission of O * 2 was found in Au-M for the higher M ratios. Surprisingly, for Au-M with lower M ratios, the barriers were much lower than for pure Au surfaces, suggesting a highly reactive surface towards the orr. The O-O scission of the OOH * was found to be a barrierless process in Au-Pt systems and nearly barrierless in all Au-Pd systems, implying that the reduction of O2 in these systems proceeds via the full reduction of O2 to H2O, avoiding H2O2 formation.

show abstract

Catalysts for oxygen reduction reaction based on nanocrystals of a Pt or Pt–Pd alloy shell supported on a Au core

Cited by 20 publications

References 60 publications

Ti/Pt−Pd‐Based Nanocomposite: Effects of Metal Oxides on the Oxygen Reduction Reaction

Ti/Pt−Pd‐Based Nanocomposite: Effects of Metal Oxides on the Oxygen Reduction Reaction

Decoupling strain and ligand effects in ternary nanoparticles for improved ORR electrocatalysis

Oxygen reduction reaction (orr) on bimetallic AuPt and AuPd(1 0 0)–electrodes: Effects of the heteroatomic junction on the reaction paths

Contact Info

Product

Resources

About