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Deutsch, J.; Quaschning, V.; Kemnitz, Erhard; Auroux, A.; Ehwald, H.; Lieske, H.

doi:10.1023/a:1009061711981

Cited by 29 publications

(14 citation statements)

References 10 publications

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“…In an earlier paper we speculated on the possibility of networks of interacting sulfonic acid groups existing in hydrated resins and being responsible for the acid strength enhancement [8]. This was based on an earlier model proposed by Gates [25] and it remains our favoured explanation for the elevated acid strengths.…”

Section: Resultsmentioning

confidence: 98%

The Influence of Solvent on the Acidity and Activity of Supported Sulfonic Acid Catalysts

Koujout

Brown

2004

Catalysis Letters

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The acid strengths and catalytic activities of sulfonic acids supported on polystyrene resins and ordered mesoporous HMS and SBA-15 silicas are compared. Acid strengths are measured by acid-base titration calorimetry in terms of the molar enthalpies of neutralisation with either NaOH or n-butylamine in water, acetonitrile and cyclohexane. Catalytic activities (turnover numbers) are reported in model reactions in water, 1,2-dichlorobenzene and anisole, and compared with acid strengths. In water, sulfonated resins are both stronger acids and more active catalysts than sulfonated silicas. Catalytic activities in water correlate well with these measured acid strengths. In acetonitrile the order of acid strengths is reversed and the sulfonated silicas are the stronger acids. Catalytic measurements in 1,2-dichlorobenzene, a similar dipolar aprotic solvent, show the same reversed order of activities. In the non-polar solvent cyclohexane (where only macroporous sulfonated resins show measurable acidity) the sulfonated silicas are again the stronger acids but by a larger margin. Catalytic activities in anisole, which is also only very weakly solvating towards sulfonic acid groups, show a similar trend. The results illustrate the role of the solvent in controlling the acid strength of solid acid catalysts, and the importance of taking this into account when designing acid catalysts for liquid phase processes.

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Section: Resultsmentioning

confidence: 98%

The Influence of Solvent on the Acidity and Activity of Supported Sulfonic Acid Catalysts

Koujout

Brown

2004

Catalysis Letters

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“…The largest number of research papers which include FT-IR/ PAS catalytic investigations belongs two scientific groups chaired by Kemnitz [124][125][126][127][128][129][130][131][132][133][134][135][136][137][138][139][140][141][142][143] and Vansant [25,100,. Kemnitz et al have applied FT-IR/PAS for pyridine adsorption [124] for the studies of surface acidity and the nature of acid sites in g-alumina [125], sulfated zirconia [126][127][128][129][130], WO 3 / ZrO 2 catalysts [131], modified zirconium and titanium dioxides [132], highly dispersed vanadium-doped metal oxides [133], chromia materials [134][135][136][137], various MgF 2 catalysts [138][139][140], and aluminium fluorides [141][142][143].…”

Section: Spectroscopic Investigationsmentioning

confidence: 99%

“…Kemnitz et al have applied FT-IR/PAS for pyridine adsorption [124] for the studies of surface acidity and the nature of acid sites in g-alumina [125], sulfated zirconia [126][127][128][129][130], WO 3 / ZrO 2 catalysts [131], modified zirconium and titanium dioxides [132], highly dispersed vanadium-doped metal oxides [133], chromia materials [134][135][136][137], various MgF 2 catalysts [138][139][140], and aluminium fluorides [141][142][143]. In the case of Vansant and co-workers IR/PAS is mostly a supplementary technique in the studies conducted with: silica and/or silicas surface and silica gel [144][145][146][147][148][149][150][151], MoO x layer on the surface of silica [152], adsorption of VO(acac) 2 or V(acac) 2 on silica and alumina [153][154][155], controlled deposition of iron oxide on the surface of zirconia [156], vanadium oxide deposited on thermally stable mesoporous titania [157].…”

Section: Spectroscopic Investigationsmentioning

confidence: 99%

Application of infrared photoacoustic spectroscopy in catalysis

Ryczkowski

2007

Catalysis Today

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“…The solid acid catalysts like molecular sieves represent a promising future for Friedel-Crafts acylations. For acylation reactions were used also other heterogeneous catalysts like mesoporous molecular sieves [2][3][4], clays, heteropoly acids [5,6], modified zirconia [7,8], Nafion [9] etc.…”

Section: Introductionmentioning

confidence: 99%

Acylations with Long-Chain Acid Anhydrides and Acyl Chlorides over Zeolite Beta

2008

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Acylation of ferrocene and toluene with linear, branched and aromatic anhydrides and chlorides of different chain length was investigated over zeolite Beta with Si/Al ratio 12.5. It was found that the conversion of ferrocene increased from acetic to butyric anhydride/chloride and then decreased with further increasing of chain length. The selectivity to 1-acylferrocene was in all cases 100%. In the case of toluene acylation, the conversions of acylating agent increased with the chain length of acylating agent up to hexanoic derivatives then the conversion of acylating agent was almost constant. The selectivity to p-isomer in toluene acylation increased with the chain length. The lowest conversions in both cases were achieved with benzoic anhydride and benzoyl chloride.

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Untitled

Cited by 29 publications

References 10 publications

The Influence of Solvent on the Acidity and Activity of Supported Sulfonic Acid Catalysts

The Influence of Solvent on the Acidity and Activity of Supported Sulfonic Acid Catalysts

Application of infrared photoacoustic spectroscopy in catalysis

Acylations with Long-Chain Acid Anhydrides and Acyl Chlorides over Zeolite Beta

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