A fundamental study of Pt impregnation of carbon: Adsorption equilibrium and particle synthesis

Hao, Xiaolin; Barnes, Sean E.; Regalbuto, John R.

doi:10.1016/j.jcat.2010.12.021

Cited by 88 publications

(65 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Impregnation was performed with an ion adsorption method where the volume of impregnation solution containing the catalyst precursor material exceeds the pore volume of carbon material. The charged precursor is bound and stabilized at the surface via Coulomb forces [83][84][85] in N 2 in a tubular reactor. 64,82 The real Pt content determined by ICP-OES was 2.8% thus the subsequent designation (2.8%) was used for Pt/TiC-CDC.…”

Section: Wt% Pt/bacmentioning

confidence: 99%

Aqueous-phase reforming of xylitol over Pt/C and Pt/TiC-CDC catalysts: catalyst characterization and catalytic performance

Кирилин

Hasse

Tokarev

et al. 2014

Catal. Sci. Technol.

View full text Add to dashboard Cite

aThe aqueous phase reforming (APR) of xylitol was studied over five Pt/C catalysts. The correlation between physico-chemical properties of the catalysts and catalytic performance was established. The Pt/C catalysts have different textural properties as well as different mean Pt cluster sizes and surface acidity. The average Pt cluster size was investigated by means of CO chemisorption as well as by TEM.The reaction was found to be structure sensitive and TOF linearly increases with increasing average Pt cluster size in the studied domain. The catalysts which possess higher surface acidity favoured higher rates of hydrocarbon production. On the contrary the Pt/C materials with lower acidities generated hydrogen with high selectivity and TOF.

show abstract

Section: Wt% Pt/bacmentioning

confidence: 99%

Aqueous-phase reforming of xylitol over Pt/C and Pt/TiC-CDC catalysts: catalyst characterization and catalytic performance

Кирилин

Hasse

Tokarev

et al. 2014

Catal. Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…Rational synthesis techniques were then developed by Regalbuto et al [11,12], initially to deposit Pt and Pd nanoparticles on inorganic supports. The technique is, however, quite versatile: it was adapted to various supports, like silica [13,14], alumina [15] and carbon [16,17], and can be extended to other metals and to bimetallic nanoparticles [18,19].…”

Section: Strong Electrostatic Adsorptionmentioning

confidence: 99%

Design of Pt/Carbon Xerogel Catalysts for PEM Fuel Cells

et al. 2015

View full text Add to dashboard Cite

Abstract:The design of efficient catalytic layers of proton exchange membrane fuel cells (PEMFCs) requires the preparation of highly-loaded and highly-dispersed Pt/C catalysts. During the last few years, our work focused on the preparation of Pt/carbon xerogel electrocatalysts, starting from simple impregnation techniques that were further optimized via the strong electrostatic adsorption (SEA) method to reach high dispersion and a high metal weight fraction. The SEA method, which consists of the optimization of the precursor/support electrostatic impregnation through an adequate choice of the impregnation pH with regard to the support surface chemistry, leads to very well-dispersed Pt/C samples with a maximum 8 wt.% Pt after drying and reduction under H2. To increase the metal loading, the impregnation-drying-reduction cycle of the SEA method can be repeated several times, either with fresh Pt precursor solution or with the solution recycled from the previous cycle. In each case, a high dispersion (Pt particle size ~3 nm) is obtained. Finally, the procedure can be simplified by combination of the SEA technique with dry impregnation, leading to no Pt loss during the procedure.

show abstract

“…With the exception of incipient wetness [23] (which yields 4.9 nm particles) these methods are somewhat complex and involve an abundance of chemical ingredients. A potentially simpler method yielding even smaller nanoparticles is Strong Electrostatic Adsorption (SEA), in which metal precursors are strongly adsorbed over support surfaces by controlling the pH of the impregnation solution and exploiting the chemistry of the nascent surface hydroxyl groups [28][29][30]. Via SEA, average nanoparticle size is normally between 1 and 2 nm.…”

Section: Introductionmentioning

confidence: 99%

“…Via SEA, average nanoparticle size is normally between 1 and 2 nm. Systematic studies of electrostatic adsorption have been made of more common carbons: amorphous activated carbon and carbon black [29,31], graphitic carbon [29] as well as amorphous carbon xerogels [30]. These materials have been demonstrated to adsorb anionic Pt chloride complexes such as Pt (IV) hexachloride (PHC), [PtCl 6 ] 2− , and cationic complexes such as Pt (II) tetraammine (PTA), [(NH 3 ) 4 Pt] 2+ , predominantly via electrostatic adsorption, with commensurate small nanoparticle size.…”

Section: Introductionmentioning

confidence: 99%

“…According to our prior studies of SEA with carbon, surface oxidation is not needed for the adsorption of anions (and is in fact deleterious to it [29]) as pi bonds in aromatic rings can be protonated, while surface oxidation, which imparts acid surface groups and renders deprotonation and negative charge at high solution pH) is needed for the uptake of cations [29][30][31]. With a variety of specialty carbons, comprised of multi-walled carbon nanotubes and nanofibers with varying surface functional groups and orientation of graphene sheets, we demonstrate that SEA can indeed be extended for anionic and cationic metal precursor adsorption over carbons of all types.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Electrostatic Adsorption of Platinum onto Carbon Nanotubes and Nanofibers for Nanoparticle Synthesis

Banerjee

Contreras-Mora

McQuiston

et al. 2018

View full text Add to dashboard Cite

Strong Electrostatic Adsorption (SEA) has been demonstrated as a simple, scientific method to prepare well dispersed Pt nanoparticles over typical forms of carbon: activated, black, and graphitic carbons. Many varieties of specialty carbons have been invented in the last few decades including multi-walled nanotubes, nanofibers, graphene nanoplatelets, etc. In this work, we explore whether SEA can be applied to these specialty carbons for the synthesis of Pt nanoparticles. Over a number of oxidized and unoxidized multiwalled nanotubes and nanofibers, the point of zero charge (PZC) was measured and the uptake of anionic Pt complexes (Pt hexachloride, [PtCl 6 ] 2− , and cationic Pt complexes (platinum tetraammine, [Pt(NH 3 ) 4 ] 2+ ) as functions of final pH were surveyed. Pt nanoparticles on the various supports were synthesized at the optimal pH and were characterized by x-ray diffraction (XRD) and scanning transmission electron microscopy (STEM). The specialty carbons displayed volcano-shaped uptake curves typical of electrostatic adsorption for both Pt anions at low pH and Pt cations at high pH. However, the regimes of uptake often did not correspond to the measured PZC, probably due to surface impurities from the carbon manufacturing process. This renders the measured PZC of these specialty carbons unreliable for predicting anion and cation uptake. On the other hand, the anion and cation uptake curves provide an "effective" PZC and do indicate the optimal pH for the synthesis of ultrasmall nanoparticle synthesis. High resolution STEM imaging also showed that with SEA it is possible to disperse nanoparticles on the surface as well as the inner walls of the specialty carbons.

show abstract

A fundamental study of Pt impregnation of carbon: Adsorption equilibrium and particle synthesis

Cited by 88 publications

References 41 publications

Aqueous-phase reforming of xylitol over Pt/C and Pt/TiC-CDC catalysts: catalyst characterization and catalytic performance

Aqueous-phase reforming of xylitol over Pt/C and Pt/TiC-CDC catalysts: catalyst characterization and catalytic performance

Design of Pt/Carbon Xerogel Catalysts for PEM Fuel Cells

Electrostatic Adsorption of Platinum onto Carbon Nanotubes and Nanofibers for Nanoparticle Synthesis

Contact Info

Product

Resources

About