Specific tuning of acid/base sites in apatite materials to enhance their methanol thiolation catalytic performances

Lamonier, Carole; Lamonier, Jean‐François; Aellach, Belaïd; Ezzamarty, A.; Leglise, J.

doi:10.1016/j.cattod.2010.10.035

Cited by 40 publications

(31 citation statements)

References 20 publications

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“…The spectra in Figure show two domains of the same IR spectra for all the apatite solids, namely, the regions at 3000–3700 cm −1 and 1700–400 cm −1 . The vibrational band in the 3000–3700 cm −1 range was observed in all the apatites and assigned to the presence of adsorbed and constitutive water molecules . A sharp band at 3572 cm −1 was observed for the Sr‐free apatites (HAp and DAp), which can be assigned to structural OH groups.…”

Section: Resultssupporting

confidence: 83%

“…The IR absorption bands attributed to phosphate groups shifted to lower wavenumbers if increasing the strontium content in apatites, as previously reported . Furthermore, the peaks at 1455 cm −1 and 1414 cm −1 can be attributed to CO 3 2− . A peak at 1350 cm −1 was observed for some solids (SrAp‐25 and SrAp‐75) and attributed to nitrate impurity from the precursors used for the synthesis …”

Section: Resultsmentioning

confidence: 69%

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Guerbet Reaction over Strontium‐Substituted Hydroxyapatite Catalysts Prepared at Various (Ca+Sr)/P Ratios

Silvester

Lamonier

et al. 2017

ChemCatChem

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The Guerbet reaction of ethanol to heavier products was performed over a series of extensively characterized Sr‐substituted hydroxyapatites (HAPs) with different (Ca+Sr)/P ratios, and thus different structural, textural, and acid–base properties. The acid–base properties were correlated with the reactivity of the solids and an optimal ratio between the amount of acid and basic sites was determined (ca. 4), whereas the ethanol conversion was mainly depending on the specific surface area of the solids. The stoichiometric 100 mol % Sr‐substituted sample (SrAp‐100) was especially efficient in higher alcohols production, which can be illustrated by a total alcohol selectivity (76.4 %) higher than that of all the other solids at a 13 % ethanol isoconversion.

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Section: Resultssupporting

confidence: 83%

Section: Resultsmentioning

confidence: 69%

Guerbet Reaction over Strontium‐Substituted Hydroxyapatite Catalysts Prepared at Various (Ca+Sr)/P Ratios

Silvester

Lamonier

et al. 2017

ChemCatChem

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“…A hot filtration was then performed and the precipitate obtained was washed by the use of hot distilled water to remove nitrates. Finally, the precipitate was placed in a pyrex vessel and was heated in an oven at 60 °C overnight 20 . The chemical elemental analysis of the obtained compound indicates that it is a deficient apatite with a Ca/P ratio of about 1.50, a specific area of 80 m 2 /g and a pore volume of 0.34 mL/g.…”

Section: Methodsmentioning

confidence: 99%

“…AOPs based on the generation of very reactive and oxidizing free radicals, especially hydroxyl radicals, have been used with an increasing interest due to their high oxidant power 18,19 . Calcium hydroxyapatites are very thermally stable products; they are handled as harmless solids to the environment and not soluble in water 20 . HAP is one of the most important bioceramics for medical and dental application such as bone reconstruction and drug delivery systems 21,22 .…”

Section: Introductionmentioning

confidence: 99%

Study of the photocatalytic degradation of methylene blue dye using titanium-doped hydroxyapatite

et al. 2015

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Organic dyes and colouring textile agents are persistent pollutant materials that are difficult to decompose by microbiological treatment processes. Their oxidation through photocatalysis is an alternative way to prevent contamination of the environment. In this work, calcium deficient hydroxyapatite (HAP) was synthesized and doped with different amounts of titanium. Its performance in photocatalytic degradation of -methylene blue dye (MB) was then demonstrated. The main parameters which govern the photocatalytic treatment efficiency, such as doped titanium amount, pH, initial concentration of MB, weight of catalyst added to solution, UV-irradiation period and bubbling oxygen-have been-investigated. Photodegradation of MB is found to be effective with HAP/11 wt. %Ti in oxygenated medium. However, pH has no significant effect on the yield of discoloration.

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“…Stoichiometric HAP was synthetized following a co-precipitation route as reported elsewhere (Campisi et al 2018;Lamonier et al 2011). Briefly summarizing, the synthesis consisted in a dropwise addition of a Ca(NO3)2•4H2O aqueous solution to a (NH4)2HPO4 solution.…”

Section: Synthesis Of Hapmentioning

confidence: 99%

Nickel and cobalt adsorption on hydroxyapatite: a study for the de-metalation of electronic industrial wastewaters

2019

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In the present study, the Ni(II) and Co(II) adsorption efficiency and selectivity, as well adsorption mechanisms on a stoichiometric hydroxyapatite (HAP) surface have been investigated. Characterization studies (N2 adsorption/desorption and X-ray powder diffraction (XRPD) analyses) and adsorption tests under various operative conditions provided detailed information about the use of HAP in the de-metalation of wastewaters containing Ni and Co as polluted metal species. The sorption capacity of HAP has been evaluated by static batch adsorption tests varying initial concentration of Ni(II) and Co(II) species (from ca. 0.25 to 4.3 mM), contact time (from 15 min to 24 h), and pH (from 4 and 9) operative parameters. Proposed mechanisms of adsorption of Ni(II) and Co(II) on HAP surface are ion-exchange and surface complexation; a partial contribution of chemical precipitation from bulk solution should be considered at pH 9. In addition, adsorption isotherms of Ni(II) and Co(II) on HAP have been collected at 30°C and pH 4 and modeled by employing different equations. The maximum sorption capacities have been quantified as 0.317 mmol g-1 HAP (18.6 mg g-1 HAP) and 0.382 mmol g-1 HAP (22.5 mg g-1 HAP) for Ni(II) and Co(II), respectively. Selectivity to Co and Ni in the adsorption process on HAP has also been investigated; HAP has higher affinity towards Co than Ni species (Co:Ni=2.5:1, molar ratio).

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Specific tuning of acid/base sites in apatite materials to enhance their methanol thiolation catalytic performances

Cited by 40 publications

References 20 publications

Guerbet Reaction over Strontium‐Substituted Hydroxyapatite Catalysts Prepared at Various (Ca+Sr)/P Ratios

Guerbet Reaction over Strontium‐Substituted Hydroxyapatite Catalysts Prepared at Various (Ca+Sr)/P Ratios

Study of the photocatalytic degradation of methylene blue dye using titanium-doped hydroxyapatite

Nickel and cobalt adsorption on hydroxyapatite: a study for the de-metalation of electronic industrial wastewaters

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