Surface features of P-doped silica: a comparison between IR spectroscopy and theoretical modelling

Cerruti, Marta; Morterra, C.; Ugliengo, Piero

doi:10.1039/b407242a

Cited by 19 publications

(32 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Cerruti et al [39,43] pioneered this approach on sol-gel bioactive glasses, and studied their surface reactivity with probe molecule-based spectroscopic and calorimetric techniques typically used to study catalysts. Experimental work in this field is paralleled by multi-scale computational models, which can provide an atomistic description of the average phenomena measured experimentally [5,8,37,38,41,[44][45][46][47]. Even though not specific on surfaces, excellent reviews of computational models of the structure and reactivity of bioactive glasses have been published recently [48,49].…”

Section: (B) Characterization Toolsmentioning

confidence: 99%

Surface characterization of silicate bioceramics

Cerruti

2012

Phil. Trans. R. Soc. A.

Self Cite

View full text Add to dashboard Cite

The success of an implanted prosthetic material is determined by the early events occurring at the interface between the material and the body. These events depend on many surface properties, with the main ones including the surface's composition, porosity, roughness, topography, charge, functional groups and exposed area. This review will portray how our understanding of the surface reactivity of silicate bioceramics has emerged and evolved in the past four decades, owing to the adoption of many complementary surface characterization tools. The review is organized in sections dedicated to a specific surface property, each describing how the property influences the body's response to the material, and the tools that have been adopted to analyse it. The final section introduces the techniques that have yet to be applied extensively to silicate bioceramics, and the information that they could provide.

show abstract

Section: (B) Characterization Toolsmentioning

confidence: 99%

Surface characterization of silicate bioceramics

Cerruti

2012

Phil. Trans. R. Soc. A.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Measured BAS densities are only reliable if the adsorbed alkylamine reacts first and does not molecularly desorb. 19,20 While this assumption holds true for bridging hydroxyls in aluminosilicates, 29 challenges associated with extending it to weak acids have been previously illustrated on [B]-substituted zeolites. 30,31 Gorte and co-workers have shown that in the course of a TPD, isopropylamine can desorb without reacting on the weakly Brønsted acidic centers of [B]-substituted MFI, leading to the undercounting of available BAS.…”

Section: Brønsted Acidicmentioning

confidence: 99%

“…For example, while Si-O-P linkages have not been detected on SPA catalyts, 16 their presence has been recently established in P-SPP. 17 Moreover, the support for SPA is either kieselguhr, 18 or pyrogenic/mesoporous silica, 19,20 while P-zeosils have been synthesized using both meso-and microporous supports. [7][8][9] Lastly, unlike SPA catalysts where only pyrophosphate phases are present, P-zeosils with low phosphorus loadings (Si/P >10) retain the crystallinity and specific surface area of the zeolitic phase.…”

mentioning

confidence: 99%

On the Acid Sites of Phosphorous Modified Zeosils

Kumar¹,

Ren²,

Pang³

et al. 2021

Preprint

View full text Add to dashboard Cite

The acid sites of phosphorus-containing zeosils were probed through a combination of solid acid characterization, density functional theory calculations, and kinetic interrogations, establishing their weakly Brønsted acidic character. Due to the disparity in acid-site strength, P-zeosils catalyzed the probe chemistry of isopropanol dehydration slower than aluminosilicate zeolites by an order of magnitude on an active site basis. Propene selectivity during isopropanol dehydration remained 20-30% higher than that of aluminosilicates, illustrating the distinct nature of the weakly acidic phosphorus active sites that favored unimolecular dehydration routes. Regardless of the confining siliceous environment, the nature of phosphorous active sites was unchanged, indicated by identical apparent uni- and bi-molecular dehydration energy barriers. Kinetic isotope experiments with deuterated isopropanol feeds implicated an E2-type elimination to propene formation on phosphorus-containing materials. Comparison of KIEs between phosphorus-containing zeosils and aluminosilicates pointed to an unchanged isopropanol dehydration mechanism, with changes in apparent energetic barriers attributed to weaker binding on phosphorous-active sites that lead to a relatively destabilized alcohol dimer adsorbate. Both ex-situ alkylamine Hofmann elimination and in-situ pyridine titration characterization methods exhibited phosphorous acid site counts dependent on probe molecules identity and/or concentration, underpinning the limitations of extending common characterization techniques for Brønsted-acid catalysis to weakly acidic materials.

show abstract

“…Phosphorus‐based materials are reported to have Brønsted acidity and have been extensively studied as catalysts, including for the catalytic upgrading of lignocellulosic biomass. For example, niobium phosphate is a selective catalyst for fructose dehydration to 5‐hydroxymethylfurfural (HMF), exhibiting 78.2 % HMF selectivity at 58 % fructose conversion .…”

Section: Introductionmentioning

confidence: 99%

“…Phosphorus-based materials [1][2][3][4][5][6][7][8][9][10][11][12] are reported to have Brønsted acidity and have been extensively studied as catalysts,i ncluding for the catalytic upgrading of lignocellulosic biomass.F or example,n iobium phosphate is as elective catalyst for fructose dehydration to 5-hydroxymethylfurfural (HMF), exhibiting 78.2 %H MF selectivity at 58 %f ructose conversion. [13] Similarly,p hosphoric acid supported on allsilica zeolites (zeosils) are highly selective catalysts in the production of p-xylene from 2,5-dimethyl furan (2,5-DMF) and ethylene.…”

Section: Introductionmentioning

confidence: 99%

Phosphonate‐Modified UiO‐66 Brønsted Acid Catalyst and Its Use in Dehydra‐Decyclization of 2‐Methyltetrahydrofuran to Pentadienes

et al. 2020

View full text Add to dashboard Cite

Phosphorus‐modified all‐silica zeolites exhibit activity and selectivity in certain Brønsted acid catalyzed reactions for biomass conversion. In an effort to achieve similar performance with catalysts having well‐defined sites, we report the incorporation of Brønsted acidity to metal–organic frameworks with the UiO‐66 topology, achieved by attaching phosphonic acid to the 1,4‐benzenedicarboxylate ligand and using it to form UiO‐66‐PO3H2 by post‐synthesis modification. Characterization reveals that UiO‐66‐PO3H2 retains stability similar to UiO‐66, and exhibits weak Brønsted acidity, as demonstrated by titrations, alcohol dehydration, and dehydra‐decyclization of 2‐methyltetrahydrofuran (2‐MTHF). For the later reaction, the reported catalyst exhibits site‐time yields and selectivity approaching that of phosphoric acid on all‐silica zeolites. Using solid‐state NMR and deprotonation energy calculations, the chemical environments of P and the corresponding acidities are determined.

show abstract

Surface features of P-doped silica: a comparison between IR spectroscopy and theoretical modelling

Cited by 19 publications

References 16 publications

Surface characterization of silicate bioceramics

Surface characterization of silicate bioceramics

On the Acid Sites of Phosphorous Modified Zeosils

Phosphonate‐Modified UiO‐66 Brønsted Acid Catalyst and Its Use in Dehydra‐Decyclization of 2‐Methyltetrahydrofuran to Pentadienes

Contact Info

Product

Resources

About