Effect of the OH−/Pt Ratio During Polyol Synthesis on Metal Loading and Particle Size in DMFC Catalysts

Aoun, Nadia; Schlange, Alicja; Santos, Antonio Rodolfo dos; Kunz, Ulrich; Turek, Thomas

doi:10.1007/s12678-015-0275-9

Cited by 12 publications

(23 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A first milestone to perform systematic studies on heterogeneous catalysts such as supported Pt NPs, is to establish a suitable strategy for the synthesis of the active phase. In many approaches, NPs are directly formed onto the support material [17,18] . This is the case in the popular and industrially relevant incipient wetness route based on impregnation‐calcination steps [1] .…”

Section: Surfactant‐free Colloidal Synthesesmentioning

confidence: 99%

See 1 more Smart Citation

Beyond Active Site Design: A Surfactant‐Free Toolbox Approach for Optimized Supported Nanoparticle Catalysts

2021

View full text Add to dashboard Cite

Developing new catalysts with superior activity, stability, and selectivity is the ultimate research goal in catalysis. However, a complete understanding of what makes new or already known supported catalysts performant is still challenging. In addition to a careful design of the catalytically active phase, properties such as the interparticle distance, the location of the active phase in the outer or inner pores of the support material, as well as preparation steps such as washing, storage conditions, and conditioning can severely affect the observed performance. With the example of supported Pt nanoparticles (NPs), it is illustrated how systematic studies, where only one experimental parameter is changed at a time independently of the others, provide detailed insights into supported heterogeneous catalyst design. To perform such studies, an integral toolbox approach based on a surfactant‐free colloidal synthesis of NPs is developed. This approach takes into account not only the design and production of the catalytically active phase but considers all steps prior to testing the catalyst. The toolbox is well suited to flag and address pitfalls beyond the active phase design, to study and optimize supported precious metal NPs for energy and chemical conversion processes.

show abstract

Section: Surfactant‐free Colloidal Synthesesmentioning

confidence: 99%

“…It also affects the charge developed on carbon material support: the higher the concentration, the more negatively charged the carbon materials. As a result, it is challenging to reach a given loading at smaller NP size due to repulsive interactions between NPs and support [17] …”

Section: Surfactant‐free Colloidal Synthesesmentioning

confidence: 99%

Beyond Active Site Design: A Surfactant‐Free Toolbox Approach for Optimized Supported Nanoparticle Catalysts

2021

View full text Add to dashboard Cite

show abstract

“…6 To obtain supported nanoparticles, the polyol process is typically performed in a 'one-pot' approach, where precious metals are directly formed on a support. 7 In one-pot syntheses it is often observed that the nature of the support influences the size [8][9] and the effect of particle size cannot be studied independently of the nature of the support, a severe drawback for systematic studies. In the absence of a support, stable colloidal dispersions of precious metal nanoparticles can be obtained.…”

Section: Introductionmentioning

confidence: 99%

Investigating Particle Size Effects in Catalysis by Applying a Size-Controlled and Surfactant-Free Synthesis of Colloidal Nanoparticles in Alkaline Ethylene Glycol: Case Study of the Oxygen Reduction Reaction on Pt

et al. 2018

View full text Add to dashboard Cite

Colloidal platinum nanoparticles are obtained via a surfactant-free polyol process in alkaline ethylene glycol. In this popular synthesis, ethylene glycol functions as solvent and reducing agent. The preparation procedure is known for its reproducibility to obtain 1-2 nm nanoparticles, but at the same time the controlled preparation of larger nanoparticles is challenging. A reliable size control without the use of surfactants is a fundamental yet missing achievement for systematic investigations. In this work it is demonstrated how the molar ratio between NaOH and the platinum precursor determines the final particle size and how this knowledge can be used to prepare and study in a systematic way supported catalysts with defined size and Pt to carbon ratio. Using small-angle X-ray scattering, transmission electron microscopy, infrared spectroscopy, X-ray absorption spectroscopy, pair distribution function and electrochemical analysis it is shown that changing the NaOH/Pt molar ratio from 25 to 3, the Pt nanoparticle size is tuned from 1 to 5 nm. This size range is of interest for various catalytic applications, such as the oxygen reduction reaction (ORR). Supporting the nanoparticles onto a high surface area carbon, we demonstrate how the particle size effect can be studied keeping the Pt to carbon ratio constant, an important aspect that in previous studies could not be accomplished.

show abstract

“…Compared with the impregnation method, the colloidal method can easily regulate and produce small, homogeneously distributed metal NPs 45 . In the past decade, the modified polyol method which is a subset of the colloidal method has also been widely researched and applied to the preparation of ORR catalysts with a loading above 50 wt.%.…”

Section: High‐loading Pt Npcsmentioning

confidence: 99%

Recent advances in high‐loading catalysts for low‐temperature fuel cells: From nanoparticle to single atom

Shen

et al. 2021

SusMat

View full text Add to dashboard Cite

Low‐temperature fuel cells (LTFCs) are considered to be one of the most promising power sources for widespread application in sustainable and renewable energy conversion technologies. Although remarkable advances have been made in the mass activity of catalysts, mass transport impedance needs to be urgently addressed at a well‐designed membrane electrode assembly (MEA) scale. Increasing the loading of electrocatalysts is conducive to prepare thinner and more efficient MEAs owing to the resulting enhanced reactant permeability, better proton diffusion, and lower electrical resistance. Herein, recent progress in high‐loading (≥40 wt.%) Pt nanoparticle catalysts (NPCs) and high‐loading (≥2 wt.%) single‐atom catalysts (SACs) for LTFC applications are reviewed. A summary of various synthetic approaches and support materials for high‐loading Pt NPCs and SACs is systematically presented. The influences of high surface area and appropriate surface functionalization for Pt NPCs, as well as coordination environment, spatial confinement effect, and strong metal‐support interactions (SMSI) for SACs are highlighted. Additionally, this review presents some ideas regarding challenges and future opportunities of high‐loading catalysts in the application of LTFCs.

show abstract

Effect of the OH−/Pt Ratio During Polyol Synthesis on Metal Loading and Particle Size in DMFC Catalysts

Cited by 12 publications

References 38 publications

Beyond Active Site Design: A Surfactant‐Free Toolbox Approach for Optimized Supported Nanoparticle Catalysts

Beyond Active Site Design: A Surfactant‐Free Toolbox Approach for Optimized Supported Nanoparticle Catalysts

Investigating Particle Size Effects in Catalysis by Applying a Size-Controlled and Surfactant-Free Synthesis of Colloidal Nanoparticles in Alkaline Ethylene Glycol: Case Study of the Oxygen Reduction Reaction on Pt

Recent advances in high‐loading catalysts for low‐temperature fuel cells: From nanoparticle to single atom

Contact Info

Product

Resources

About