Solid-state NMR characterization of the acid sites in cubic mesoporous Al-MCM-48 materials using trimethylphosphine oxide as a 31P NMR probe

Kao, Hsien Ming; Chang, Pai Ching; Liao, Yun Wen; Lee, Lung Ping; Chien, Chu Hua

doi:10.1016/j.micromeso.2008.01.021

Cited by 31 publications

(14 citation statements)

References 36 publications

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“…This proton results in a Brønsted acid site, which is actually a strong acid site. Therefore, when the Al/Si ratio increases, the number of strong acid sites is higher if all the cations are replaced by protons (Huang et al, 2008;Kao, Chang, Liao, Lee, & Chien, 2008;Krithiga et al, 2005;Ribeiro Carrott et al, 2006). As mentioned before, the catalyst precursor (RuCl3) used for the synthesis may the responsible for the high acidity of the RuCl3-based catalysts and therefore, for their better performance (Guisnet et al, 1993).…”

Section: B) Effect Of Temperaturementioning

confidence: 99%

Extraction of arabinoxylans from wheat bran using hydrothermal processes assisted by heterogeneous catalysts

Sanchez‐Bastardo

Romero

Alonso

2017

Carbohydrate Polymers

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The extraction/hydrolysis process of arabinoxylans from destarched wheat bran was studied in this work using different mesoporous silica supports and the corresponding RuCl3-based catalysts. The effects of temperature, time, catalyst supports and ruthenium catalysts were investigated and discussed in terms of the arabinoxylans extraction yield and their polymerization degree. Relatively high temperatures (180 ºC), short extraction times (10 minutes) and RuCl3 supported on Al-MCM-48 led to a high amount of arabinoxylans extracted (78%) with a low molecular weight (9 KDa). Finally, a relation between the operating conditions, the arabinoxylans extraction yield and the molecular weight was stablished based on the obtained results. Abbreviation: AXs, arabinoxylans; DWB, destarched wheat branKeywords: Hemicelluloses fractionation, wheat bran, arabinoxylans, heterogeneous catalysis, hydrothermal process, biomass Chemical compounds studied in this articleXylose (PubChem CID: 135191); Arabinose (PubChem CID: 439195) Highlights:-Effects of ruthenium catalyst, temperature, time and catalyst support are discussed -RuCl3-based catalysts show good activity for the arabinoxylans extraction from wheat bran -Liquid extracts are characterized in terms of sugars, molecular weight and purity

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Section: B) Effect Of Temperaturementioning

confidence: 99%

Extraction of arabinoxylans from wheat bran using hydrothermal processes assisted by heterogeneous catalysts

Sanchez‐Bastardo

Romero

Alonso

2017

Carbohydrate Polymers

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“…Indeed, R 3 PO molecules have been shown to be more practical in revealing the strengths and distributions of acid sites, in various solid acids. [73][74][75] Among the R 3 PO homologues, a more extensive solid-state 31 P NMR study on acidity characterization of solid acids has been conducted using TMPO as the probe molecule. On the basis of our past experiences on such ( 31 P-R 3 PO) approach, a standard operation procedure was developed for guest molecule (TMPO and TBPO) adsorption and relevant experimental considerations, as shown in Scheme 2.…”

Section: Trialkylphosphine Oxides (R 3 Po) As Probesmentioning

confidence: 99%

“…An extensive investigation has been made by our groups and others in the past decade invoking the 31 P-TMPO approach for acidity characterization of various solid acids, including microporous zeolites (H-ZSM-5, 37 H-Mordenite, 45,77 H-Beta, 45 MCM-22, 78 and Mo/MCM-22), 75 mesoporous molecular sieves (SBA-15, 50 MCM-41, 37,74 MCM-48, 73 and SO 3 /MSU), 79 heteropolyacids (HPW 80 and HPMo), 81 supported metal oxide catalysts (VO x /Al 2 O 3 and VO x /ZrO 2 ), 82 and sulfated and metal-promoted ZrO 2 . 83 Alternatively, perdeuterated TMPO-d 9 has been used for acidity characterization 24 by using various multi-nuclei MAS NMR techniques such as CP, 84,85 TRAPDOR, [86][87][88] and REDOR.…”

Section: Trialkylphosphine Oxides (R 3 Po) As Probesmentioning

confidence: 99%

Acid properties of solid acid catalysts characterized by solid-state 31P NMR of adsorbed phosphorous probe molecules

Zheng

Huang

Liu

et al. 2011

Phys. Chem. Chem. Phys.

208

249

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A brief review is presented on acidity characterization of solid acid catalysts by means of solid-state phosphor-31 magic-angle-spinning nuclear magnetic resonance ((31)P MAS NMR) spectroscopy using phosphor-containing molecules as probes. It is emphasized that such a simple approach using (31)P MAS NMR of adsorbed phosphorous probe molecules, namely trimethylphosphine (TMP) and trialkylphosphine oxides (R(3)PO), represents a unique technique in providing detailed qualitative and quantitative features, viz. type, strength, distribution, and concentration of acid sites in solid acid catalysts. In particular, it will be shown that when applied with a proper choice of probe molecules with varied sizes and results obtained from elemental analysis, the amounts and locations (intracrystalline vs. extracrystalline) of different types (Brønsted vs. Lewis) of acid sites may be determined. In addition, by incorporating the NMR results with that obtained from theoretical density functional theory (DFT) calculations, correlations between the (31)P chemical shifts (δ(31)P) and acidic strengths of Brønsted and Lewis acid sites may also be derived, facilitating a suitable acidity scale for solid acid catalysts.

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“…Solid-state NMR has been extensively used in the characterization of MMs and some recent review articles have already dedicated some relative attention to this topic [14,[107][108][109]. Generally speaking, the domain of MM is very broad and many NMR studies have investigated specific aspects such as structure [110][111][112][113][114][115][116][117][118][119][120][121][122][123][124], interactions at interfaces [8,[125][126][127][128][129][130][131][132][133][134][135][136][137][138][139][140][141][142][143][144], confinement of organic molecules within nanopores [145][146][147][148][149][150][151]…”

Section: Mesostructured Materialsmentioning

confidence: 99%

“…be exploited for structural elucidation only after 2004: HETCOR [117,118,124], DQ excitation [116,118], rotor-synchronized double resonance (TRAnsfer of Population in DOuble Resonance (TRAPDOR), REDOR, REAPDOR) [117,119,122,123], and J-derived [116,131] experiments became unique investigation tools that allowed direct proof for spatial proximities and direct network connectivities. An example of each is detailed below.…”

Section: Structurementioning

confidence: 99%

Application of Advanced Solid‐State NMR Techniques to the Characterization of Nanomaterials: A Focus on Interfaces and Structure

Baccile

2010

Ideas in Chemistry and Molecular Sciences

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Solid-state NMR characterization of the acid sites in cubic mesoporous Al-MCM-48 materials using trimethylphosphine oxide as a 31P NMR probe

Cited by 31 publications

References 36 publications

Extraction of arabinoxylans from wheat bran using hydrothermal processes assisted by heterogeneous catalysts

Extraction of arabinoxylans from wheat bran using hydrothermal processes assisted by heterogeneous catalysts

Acid properties of solid acid catalysts characterized by solid-state 31P NMR of adsorbed phosphorous probe molecules

Application of Advanced Solid‐State NMR Techniques to the Characterization of Nanomaterials: A Focus on Interfaces and Structure

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