Experimental determination of oxygen and nitrogen solubility in organic solvents up to 10 MPa at temperatures between 298 K and 398 K

Fischer, Kai; Wilken, Michael

doi:10.1006/jcht.2001.0837

Cited by 123 publications

(126 citation statements)

References 14 publications

Supporting

Mentioning

117

Contrasting

Order By: Relevance

“…It is interesting to consider whether dissolved oxygen could re-oxidise palladium nanoparticles reduced insitu, and thus regenerate catalytic selox activity. We have only ever observed palladium re-oxidation and associated reactivation during vapour phase selox experiments [17][18] at (i) significantly higher temperatures (140 °C) than those used in the present liquid phase study (90 °C), and (ii) local oxygen concentrations far exceeding those employed during our solution phase experiments (mol fraction vapour = 0.025 versus mol fraction toluene = 0.0009 [57]), or following a deliberate post-reaction 500 C calcination treatment [22] wherein the calcined catalyst exhibits a comparable PdO content to that of fresh catalysts. The forcing conditions required to re-oxidise palladium nanoparticles suggest that the deactivated metal/carbide surfaces may be poisoned by strongly adsorbed hydrocarbons, and hence are resistant to mild re-oxidation treatments -this hypothesis is supported by comparing C 1s XP spectra of fresh and spent 0.42 wt% Pd/SBA-16 catalysts ( Figure S9).…”

Section: Operando Xas Studies Of Cinnamyl Alcohol Seloxmentioning

confidence: 67%

“…Pd(0) reoxidation back to PdO thus likely requires thermal activation; this poses a problem for solution phase regeneration, with Henry's Law dictating a decrease in oxygen solubility with increasing solution temperature. We therefore predict that palladium re-oxidation at 90 C would only be feasible under pO 2 >20 bar for which the mol fraction of dissolved oxygen rises to 0.025 [57].…”

Section: Operando Xas Studies Of Cinnamyl Alcohol Seloxmentioning

confidence: 91%

See 1 more Smart Citation

Alumina-grafted SBA-15 as a high performance support for Pd-catalysed cinnamyl alcohol selective oxidation

et al. 2014

View full text Add to dashboard Cite

eprints@whiterose.ac.uk https://eprints.whiterose.ac.uk/ Reuse Unless indicated otherwise, fulltext items are protected by copyright with all rights reserved. The copyright exception in section 29 of the Copyright, Designs and Patents Act 1988 allows the making of a single copy solely for the purpose of non-commercial research or private study within the limits of fair dealing. The publisher or other rights-holder may allow further reproduction and re-use of this version -refer to the White Rose Research Online record for this item. Where records identify the publisher as the copyright holder, users can verify any specific terms of use on the publisher's website. TakedownIf you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing eprints@whiterose.ac.uk including the URL of the record and the reason for the withdrawal request. Operando, liquid phase XAS highlights the interplay between dissolved oxygen and the oxidation state of palladium nanoparticles dispersed over Al-SBA-15 towards on-stream reduction: ambient pressures of flowing oxygen are sufficient to hinder palladium oxide reduction to metal, enabling a high selox activity to be maintained, whereas rapid PdO reduction and concomitant catalyst deactivation occurs under static oxygen.Selectivity to the desired cinnamaldehyde product mirrors these trends in activity, with flowing oxygen minimising C-O cleavage of the cinnamyl alcohol reactant to trans--methylstyrene, and of cinnamaldehyde decarbonylation to styrene. Highlights: An ultrathin alumina coating has been grafted onto a SBA-15 mesoporous silica architecture. Pd impregnated Al-SBA-15 materials are superior catalysts for the aerobic selox of allylic alcohols to aldehydes compared to pure silica or alumina supports.  Operando XAS confirms cinnamyl alcohol selox occurs over a PdO active species, which is prone to on-stream reduction and associated catalyst deactivation under static oxygen. [20,21] have highlighted PdO reduction to metallic palladium as a potential deactivation pathway, and hence the importance of generating highly dispersed nanoparticles which favour an oxide phase [20,[22][23][24]. KeywordsTemperature-programmed desorption and XPS of crotyl alcohol (but-2-en-1-ol) and crotonaldehyde (but-2-en-1-al) over Pd(111) and palladium-rich Au/Pd surface alloys suggest deactivation arises from crotonaldehyde decarbonylation and subsequent site-blocking by strongly adsorbed propylidyne and CO [20,21]. Computational modelling predicts Pd(111) can also drive propanoic acid decarbonylation [25]. Vapour phase studies of crotyl alcohol oxidation show that such in-situ palladium reduction is reversible under oxidising environments [17,19], enabling selox to be maintained, however the ability of dissolved oxygen to preserve palladium as PdO during liquid phase selox is unknown. Experimental Catalyst synthesisThe parent SBA-15 silica framework was synthesised following the method of Zhao et al [30]. Pluronic P123 (10 g) was dissolved in water (75.5 ...

show abstract

Section: Operando Xas Studies Of Cinnamyl Alcohol Seloxmentioning

confidence: 67%

Section: Operando Xas Studies Of Cinnamyl Alcohol Seloxmentioning

confidence: 91%

Alumina-grafted SBA-15 as a high performance support for Pd-catalysed cinnamyl alcohol selective oxidation

et al. 2014

View full text Add to dashboard Cite

show abstract

“…Since the solubility of air is higher in ethanol than it is in an aqueous solution [60], replacing ethanol with water is expected to result in the evolution of gas, some of which is trapped at the fluid-solid interface in the form of nanobubbles. The generation of such nanobubbles after ethanol-water solvent exchanges has been demonstrated on OTS-slicon surfaces via tapping mode AFM microscopy [39].…”

Section: Solvent Exchange Experimentsmentioning

confidence: 99%

Transient ζ‐potential measurements in hydrophobic, TOPAS microfluidic substrates

2009

View full text Add to dashboard Cite

We utilize time-resolved electrokinetic measurements in order to study the electrokinetic properties of silica and TOPAS microfluidic channels as a function of the time history of the fluid-solid interface. In pressure-driven flow through TOPAS microchannels, the zeta-potential as inferred from streaming potential measurements decays exponentially by a factor of 1.5 with a characteristic decay time of 3 h after the initial formation of the fluid-solid interface. A similar exponential decay is observed immediately after water is exchanged for ethanol as the solvent in the system. In electroosmotically driven flow through TOPAS microchannels, the zeta-potential as inferred through current monitoring experiments was constant in time. No electrokinetic transients were observed in silica microchannels under these flow conditions.

show abstract

“…Katayama and Nitta (1976) obtained the solubilities of nitrogen for several alcohols, among them ethanol, which are expressed in terms of Ostwald's coeff cient and Henry's constant. Fischer and Wilken (2001) studied the nitrogen solubility in organic solvents and their results are given directly in terms of molar fraction for different pressures and temperatures. In these two articles there is not any temperature correction, nor the necessary data to apply Van't Hoff equation.…”

Section: Deaerated and Saturated Conditionsmentioning

confidence: 99%

Fluid hammer with gas desorption in a liquid-filling tube: experiments with three different liquids

et al. 2015

View full text Add to dashboard Cite

Experimental determination of oxygen and nitrogen solubility in organic solvents up to 10 MPa at temperatures between 298 K and 398 K

Cited by 123 publications

References 14 publications

Alumina-grafted SBA-15 as a high performance support for Pd-catalysed cinnamyl alcohol selective oxidation

Alumina-grafted SBA-15 as a high performance support for Pd-catalysed cinnamyl alcohol selective oxidation

Transient ζ‐potential measurements in hydrophobic, TOPAS microfluidic substrates

Fluid hammer with gas desorption in a liquid-filling tube: experiments with three different liquids

Contact Info

Product

Resources

About